diff --git a/jey_erp/custom_fields.py b/jey_erp/custom_fields.py
index 7e1331b..df663f7 100644
--- a/jey_erp/custom_fields.py
+++ b/jey_erp/custom_fields.py
@@ -110,6 +110,16 @@ def create_custom_fields():
                 insert_after='item_name',
                 in_list_view=0,
                 in_standard_filter=0
+            ),
+            # Product Category field
+            dict(
+                fieldname='product_category',
+                label='Product Category',
+                fieldtype='Link',
+                options='Item Category',
+                insert_after='product_group_code',
+                in_list_view=1,
+                in_standard_filter=1
             )
         ],        
         "Bank": [
diff --git a/jey_erp/hooks.py b/jey_erp/hooks.py
index 355d677..12d230a 100644
--- a/jey_erp/hooks.py
+++ b/jey_erp/hooks.py
@@ -28,8 +28,8 @@ doc_events = {
         "on_update": "jey_erp.custom_employee_onboarding.on_update"
     },
     "Sales Invoice": {
-        "validate": "jey_erp.jey_erp.custom.sales_invoice.calculate_tax_free_amounts",
-        "on_update": "jey_erp.jey_erp.custom.sales_invoice.calculate_tax_free_amounts",
+        "validate": "jey_erp.custom.sales_invoice.calculate_tax_free_amounts",
+        "on_update": "jey_erp.custom.sales_invoice.calculate_tax_free_amounts",
     }
 }
 
diff --git a/jey_erp/jey_erp/doctype/item_category/__init__.py b/jey_erp/jey_erp/doctype/item_category/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/jey_erp/jey_erp/doctype/item_category/item_category.js b/jey_erp/jey_erp/doctype/item_category/item_category.js
new file mode 100644
index 0000000..b131ee6
--- /dev/null
+++ b/jey_erp/jey_erp/doctype/item_category/item_category.js
@@ -0,0 +1,8 @@
+// Copyright (c) 2025, JeyERP and contributors
+// For license information, please see license.txt
+
+// frappe.ui.form.on("Item Category", {
+// 	refresh(frm) {
+
+// 	},
+// });
diff --git a/jey_erp/jey_erp/doctype/item_category/item_category.json b/jey_erp/jey_erp/doctype/item_category/item_category.json
new file mode 100644
index 0000000..2111c16
--- /dev/null
+++ b/jey_erp/jey_erp/doctype/item_category/item_category.json
@@ -0,0 +1,151 @@
+{
+  "actions": [],
+  "allow_rename": 1,
+  "autoname": "field:category_name",
+  "creation": "2025-08-01 12:00:00.000000",
+  "doctype": "DocType",
+  "engine": "InnoDB",
+  "field_order": [
+    "category_name",
+    "category_code",
+    "column_break_3",
+    "parent_category",
+    "is_group",
+    "section_break_6",
+    "description",
+    "column_break_8",
+    "is_active"
+  ],
+  "fields": [
+    {
+      "fieldname": "category_name",
+      "fieldtype": "Data",
+      "in_list_view": 1,
+      "in_standard_filter": 1,
+      "label": "Category Name",
+      "reqd": 1,
+      "unique": 1
+    },
+    {
+      "fieldname": "category_code",
+      "fieldtype": "Data",
+      "in_list_view": 1,
+      "in_standard_filter": 1,
+      "label": "Category Code",
+      "unique": 1
+    },
+    {
+      "fieldname": "column_break_3",
+      "fieldtype": "Column Break"
+    },
+    {
+      "fieldname": "parent_category",
+      "fieldtype": "Link",
+      "ignore_user_permissions": 1,
+      "in_list_view": 1,
+      "in_standard_filter": 1,
+      "label": "Parent Category",
+      "options": "Item Category"
+    },
+    {
+      "default": "0",
+      "fieldname": "is_group",
+      "fieldtype": "Check",
+      "in_list_view": 1,
+      "in_standard_filter": 1,
+      "label": "Is Group"
+    },
+    {
+      "fieldname": "section_break_6",
+      "fieldtype": "Section Break"
+    },
+    {
+      "fieldname": "description",
+      "fieldtype": "Text Editor",
+      "label": "Description"
+    },
+    {
+      "fieldname": "column_break_8",
+      "fieldtype": "Column Break"
+    },
+    {
+      "default": "1",
+      "fieldname": "is_active",
+      "fieldtype": "Check",
+      "in_list_view": 1,
+      "in_standard_filter": 1,
+      "label": "Is Active"
+    }
+  ],
+  "index_web_pages_for_search": 1,
+  "links": [],
+  "modified": "2025-08-01 12:00:00.000000",
+  "modified_by": "Administrator",
+  "module": "Jey ERP",
+  "name": "Item Category",
+  "naming_rule": "By fieldname",
+  "owner": "Administrator",
+  "permissions": [
+    {
+      "create": 1,
+      "delete": 1,
+      "email": 1,
+      "export": 1,
+      "print": 1,
+      "read": 1,
+      "report": 1,
+      "role": "Stock Manager",
+      "share": 1,
+      "write": 1
+    },
+    {
+      "create": 1,
+      "delete": 1,
+      "email": 1,
+      "export": 1,
+      "print": 1,
+      "read": 1,
+      "report": 1,
+      "role": "Stock User",
+      "share": 1,
+      "write": 1
+    },
+    {
+      "create": 1,
+      "delete": 1,
+      "email": 1,
+      "export": 1,
+      "print": 1,
+      "read": 1,
+      "report": 1,
+      "role": "Item Manager",
+      "share": 1,
+      "write": 1
+    },
+    {
+      "email": 1,
+      "export": 1,
+      "print": 1,
+      "read": 1,
+      "report": 1,
+      "role": "Sales User",
+      "share": 1
+    },
+    {
+      "email": 1,
+      "export": 1,
+      "print": 1,
+      "read": 1,
+      "report": 1,
+      "role": "Purchase User",
+      "share": 1
+    }
+  ],
+  "search_fields": "category_code,parent_category",
+  "show_name_in_global_search": 1,
+  "sort_field": "modified",
+  "sort_order": "DESC",
+  "states": [],
+  "title_field": "category_name",
+  "track_changes": 1
+}
\ No newline at end of file
diff --git a/jey_erp/jey_erp/doctype/item_category/item_category.py b/jey_erp/jey_erp/doctype/item_category/item_category.py
new file mode 100644
index 0000000..86fde56
--- /dev/null
+++ b/jey_erp/jey_erp/doctype/item_category/item_category.py
@@ -0,0 +1,9 @@
+# Copyright (c) 2025, JeyERP and contributors
+# For license information, please see license.txt
+
+# import frappe
+from frappe.model.document import Document
+
+
+class ItemCategory(Document):
+	pass
diff --git a/jey_erp/jey_erp/doctype/item_category/test_item_category.py b/jey_erp/jey_erp/doctype/item_category/test_item_category.py
new file mode 100644
index 0000000..91f652b
--- /dev/null
+++ b/jey_erp/jey_erp/doctype/item_category/test_item_category.py
@@ -0,0 +1,30 @@
+# Copyright (c) 2025, JeyERP and Contributors
+# See license.txt
+
+# import frappe
+from frappe.tests import IntegrationTestCase, UnitTestCase
+
+
+# On IntegrationTestCase, the doctype test records and all
+# link-field test record depdendencies are recursively loaded
+# Use these module variables to add/remove to/from that list
+EXTRA_TEST_RECORD_DEPENDENCIES = []  # eg. ["User"]
+IGNORE_TEST_RECORD_DEPENDENCIES = []  # eg. ["User"]
+
+
+class UnitTestItemCategory(UnitTestCase):
+	"""
+	Unit tests for ItemCategory.
+	Use this class for testing individual functions and methods.
+	"""
+
+	pass
+
+
+class IntegrationTestItemCategory(IntegrationTestCase):
+	"""
+	Integration tests for ItemCategory.
+	Use this class for testing interactions between multiple components.
+	"""
+
+	pass
diff --git a/jey_erp/patches/replace_install_function.py b/jey_erp/patches/replace_install_function.py
new file mode 100644
index 0000000..ebe72b8
--- /dev/null
+++ b/jey_erp/patches/replace_install_function.py
@@ -0,0 +1,351 @@
+# your_app/patches/replace_install_function.py
+
+import json
+import os
+from pathlib import Path
+
+import frappe
+from frappe.desk.doctype.global_search_settings.global_search_settings import (
+    update_global_search_doctypes,
+)
+from frappe.desk.page.setup_wizard.setup_wizard import make_records
+from frappe.utils import cstr, getdate
+
+from erpnext.accounts.doctype.account.account import RootNotEditable
+from erpnext.regional.address_template.setup import set_up_address_templates
+
+
+def _(x, *args, **kwargs):
+    """Redefine the translation function to return the string as is.
+
+    We want to create english records but still mark the strings as translatable.
+    The respective DocTypes have 'Translate Link Fields' enabled."""
+    return x
+
+
+def read_lines(filename: str) -> list[str]:
+    """Return a list of lines from a file in the data directory."""
+    return (Path(__file__).parent.parent / "data" / filename).read_text().splitlines()
+
+
+def custom_install(country=None):
+    """Ваша замененная функция install - вставьте сюда ваш код"""
+    records = [
+        # ensure at least an empty Address Template exists for this Country
+        {"doctype": "Address Template", "country": country},
+        # item group
+        {
+            "doctype": "Item Group",
+            "item_group_name": _("Bütün Element Qrupları"),
+            "is_group": 1,
+            "parent_item_group": "",
+        },
+        {
+            "doctype": "Item Group",
+            "item_group_name": _("Məhsullar"),
+            "is_group": 0,
+            "parent_item_group": _("Bütün Element Qrupları"),
+            "show_in_website": 1,
+        },
+        {
+            "doctype": "Item Group",
+            "item_group_name": _("Xammal"),
+            "is_group": 0,
+            "parent_item_group": _("Bütün Element Qrupları"),
+        },
+        {
+            "doctype": "Item Group",
+            "item_group_name": _("Xidmətlər"),
+            "is_group": 0,
+            "parent_item_group": _("Bütün Element Qrupları"),
+        },
+        {
+            "doctype": "Item Group",
+            "item_group_name": _("Alt məclislər"),
+            "is_group": 0,
+            "parent_item_group": _("Bütün Element Qrupları"),
+        },
+        {
+            "doctype": "Item Group",
+            "item_group_name": _("İstehlak materialı"),
+            "is_group": 0,
+            "parent_item_group": _("Bütün Element Qrupları"),
+        },
+        # Stock Entry Type
+        {
+            "doctype": "Stock Entry Type",
+            "name": _("Material Issue"),
+            "purpose": "Material Issue",
+            "is_standard": 1,
+        },
+        {
+            "doctype": "Stock Entry Type",
+            "name": _("Material Receipt"),
+            "purpose": "Material Receipt",
+            "is_standard": 1,
+        },
+        {
+            "doctype": "Stock Entry Type",
+            "name": _("Material Transfer"),
+            "purpose": "Material Transfer",
+            "is_standard": 1,
+        },
+        {
+            "doctype": "Stock Entry Type",
+            "name": _("Manufacture"),
+            "purpose": "Manufacture",
+            "is_standard": 1,
+        },
+        {
+            "doctype": "Stock Entry Type",
+            "name": _("Repack"),
+            "purpose": "Repack",
+            "is_standard": 1,
+        },
+        {"doctype": "Stock Entry Type", "name": "Disassemble", "purpose": "Disassemble", "is_standard": 1},
+        {
+            "doctype": "Stock Entry Type",
+            "name": _("Send to Subcontractor"),
+            "purpose": "Send to Subcontractor",
+            "is_standard": 1,
+        },
+        {
+            "doctype": "Stock Entry Type",
+            "name": _("Material Transfer for Manufacture"),
+            "purpose": "Material Transfer for Manufacture",
+            "is_standard": 1,
+        },
+        {
+            "doctype": "Stock Entry Type",
+            "name": _("Material Consumption for Manufacture"),
+            "purpose": "Material Consumption for Manufacture",
+            "is_standard": 1,
+        },
+        # territory: with two default territories, one for home country and one named Rest of the World
+        {
+            "doctype": "Territory",
+            "territory_name": _("All Territories"),
+            "is_group": 1,
+            "name": _("All Territories"),
+            "parent_territory": "",
+        },
+        {
+            "doctype": "Territory",
+            "territory_name": country.replace("'", ""),
+            "is_group": 0,
+            "parent_territory": _("All Territories"),
+        },
+        {
+            "doctype": "Territory",
+            "territory_name": _("Rest Of The World"),
+            "is_group": 0,
+            "parent_territory": _("All Territories"),
+        },
+        # customer group
+        {
+            "doctype": "Customer Group",
+            "customer_group_name": _("All Customer Groups"),
+            "is_group": 1,
+            "name": _("All Customer Groups"),
+            "parent_customer_group": "",
+        },
+        {
+            "doctype": "Customer Group",
+            "customer_group_name": _("Individual"),
+            "is_group": 0,
+            "parent_customer_group": _("All Customer Groups"),
+        },
+        {
+            "doctype": "Customer Group",
+            "customer_group_name": _("Commercial"),
+            "is_group": 0,
+            "parent_customer_group": _("All Customer Groups"),
+        },
+        {
+            "doctype": "Customer Group",
+            "customer_group_name": _("Non Profit"),
+            "is_group": 0,
+            "parent_customer_group": _("All Customer Groups"),
+        },
+        {
+            "doctype": "Customer Group",
+            "customer_group_name": _("Government"),
+            "is_group": 0,
+            "parent_customer_group": _("All Customer Groups"),
+        },
+        # supplier group
+        {
+            "doctype": "Supplier Group",
+            "supplier_group_name": _("All Supplier Groups"),
+            "is_group": 1,
+            "name": _("All Supplier Groups"),
+            "parent_supplier_group": "",
+        },
+        {
+            "doctype": "Supplier Group",
+            "supplier_group_name": _("Xidmətlər"),
+            "is_group": 0,
+            "parent_supplier_group": _("All Supplier Groups"),
+        },
+        {
+            "doctype": "Supplier Group",
+            "supplier_group_name": _("Local"),
+            "is_group": 0,
+            "parent_supplier_group": _("All Supplier Groups"),
+        },
+        {
+            "doctype": "Supplier Group",
+            "supplier_group_name": _("Xammal"),
+            "is_group": 0,
+            "parent_supplier_group": _("All Supplier Groups"),
+        },
+        {
+            "doctype": "Supplier Group",
+            "supplier_group_name": _("Electrical"),
+            "is_group": 0,
+            "parent_supplier_group": _("All Supplier Groups"),
+        },
+        {
+            "doctype": "Supplier Group",
+            "supplier_group_name": _("Hardware"),
+            "is_group": 0,
+            "parent_supplier_group": _("All Supplier Groups"),
+        },
+        {
+            "doctype": "Supplier Group",
+            "supplier_group_name": _("Pharmaceutical"),
+            "is_group": 0,
+            "parent_supplier_group": _("All Supplier Groups"),
+        },
+        {
+            "doctype": "Supplier Group",
+            "supplier_group_name": _("Distributor"),
+            "is_group": 0,
+            "parent_supplier_group": _("All Supplier Groups"),
+        },
+        # Sales Person
+        {
+            "doctype": "Sales Person",
+            "sales_person_name": _("Sales Team"),
+            "is_group": 1,
+            "parent_sales_person": "",
+        },
+        # Mode of Payment
+        {
+            "doctype": "Mode of Payment",
+            "mode_of_payment": "Check" if country == "United States" else _("Cheque"),
+            "type": "Bank",
+        },
+        {"doctype": "Mode of Payment", "mode_of_payment": _("Cash"), "type": "Cash"},
+        {"doctype": "Mode of Payment", "mode_of_payment": _("Credit Card"), "type": "Bank"},
+        {"doctype": "Mode of Payment", "mode_of_payment": _("Wire Transfer"), "type": "Bank"},
+        {"doctype": "Mode of Payment", "mode_of_payment": _("Bank Draft"), "type": "Bank"},
+        # Activity Type
+        {"doctype": "Activity Type", "activity_type": _("Planning")},
+        {"doctype": "Activity Type", "activity_type": _("Research")},
+        {"doctype": "Activity Type", "activity_type": _("Proposal Writing")},
+        {"doctype": "Activity Type", "activity_type": _("Execution")},
+        {"doctype": "Activity Type", "activity_type": _("Communication")},
+        {
+            "doctype": "Item Attribute",
+            "attribute_name": _("Size"),
+            "item_attribute_values": [
+                {"attribute_value": _("Extra Small"), "abbr": "XS"},
+                {"attribute_value": _("Small"), "abbr": "S"},
+                {"attribute_value": _("Medium"), "abbr": "M"},
+                {"attribute_value": _("Large"), "abbr": "L"},
+                {"attribute_value": _("Extra Large"), "abbr": "XL"},
+            ],
+        },
+        {
+            "doctype": "Item Attribute",
+            "attribute_name": _("Colour"),
+            "item_attribute_values": [
+                {"attribute_value": _("Red"), "abbr": "RED"},
+                {"attribute_value": _("Green"), "abbr": "GRE"},
+                {"attribute_value": _("Blue"), "abbr": "BLU"},
+                {"attribute_value": _("Black"), "abbr": "BLA"},
+                {"attribute_value": _("White"), "abbr": "WHI"},
+            ],
+        },
+        # Issue Priority
+        {"doctype": "Issue Priority", "name": _("Low")},
+        {"doctype": "Issue Priority", "name": _("Medium")},
+        {"doctype": "Issue Priority", "name": _("High")},
+        {"doctype": "Email Account", "email_id": "sales@example.com", "append_to": "Opportunity"},
+        {"doctype": "Email Account", "email_id": "support@example.com", "append_to": "Issue"},
+        {"doctype": "Party Type", "party_type": "Customer", "account_type": "Receivable"},
+        {"doctype": "Party Type", "party_type": "Supplier", "account_type": "Payable"},
+        {"doctype": "Party Type", "party_type": "Employee", "account_type": "Payable"},
+        {"doctype": "Party Type", "party_type": "Shareholder", "account_type": "Payable"},
+        {"doctype": "Opportunity Type", "name": _("Sales")},
+        {"doctype": "Opportunity Type", "name": _("Support")},
+        {"doctype": "Opportunity Type", "name": _("Maintenance")},
+        {"doctype": "Project Type", "project_type": _("Internal")},
+        {"doctype": "Project Type", "project_type": _("External")},
+        {"doctype": "Project Type", "project_type": _("Other")},
+        {"doctype": "Print Heading", "print_heading": _("Credit Note")},
+        {"doctype": "Print Heading", "print_heading": _("Debit Note")},
+        # Share Management
+        {"doctype": "Share Type", "title": _("Equity")},
+        {"doctype": "Share Type", "title": _("Preference")},
+        # Market Segments
+        {"doctype": "Market Segment", "market_segment": _("Lower Income")},
+        {"doctype": "Market Segment", "market_segment": _("Middle Income")},
+        {"doctype": "Market Segment", "market_segment": _("Upper Income")},
+        # Warehouse Type
+        {"doctype": "Warehouse Type", "name": "Transit"},
+    ]
+
+    for doctype, title_field, filename in (
+        ("Designation", "designation_name", "designation.txt"),
+        ("Sales Stage", "stage_name", "sales_stage.txt"),
+        ("Industry Type", "industry", "industry_type.txt"),
+        ("UTM Source", "name", "marketing_source.txt"),
+        ("Sales Partner Type", "sales_partner_type", "sales_partner_type.txt"),
+    ):
+        records += [{"doctype": doctype, title_field: title} for title in read_lines(filename)]
+
+    base_path = frappe.get_app_path("erpnext", "stock", "doctype")
+    response = frappe.read_file(os.path.join(base_path, "delivery_trip/dispatch_notification_template.html"))
+
+    records += [
+        {
+            "doctype": "Email Template",
+            "name": _("Dispatch Notification"),
+            "response": response,
+            "subject": _("Your order is out for delivery!"),
+            "owner": frappe.session.user,
+        }
+    ]
+
+    # Records for the Supplier Scorecard
+    from erpnext.buying.doctype.supplier_scorecard.supplier_scorecard import make_default_records
+
+    make_default_records()
+    make_records(records)
+    set_up_address_templates(default_country=country)
+    
+    # Импортируем функции из оригинального модуля
+    from erpnext.setup.setup_wizard.operations.install_fixtures import (
+        update_selling_defaults,
+        update_buying_defaults,
+        add_uom_data,
+        update_item_variant_settings
+    )
+    
+    update_selling_defaults()
+    update_buying_defaults()
+    add_uom_data()
+    update_item_variant_settings()
+    update_global_search_doctypes()
+
+
+def execute():
+    """Функция для применения monkey patch"""
+    import erpnext.setup.setup_wizard.operations.install_fixtures as install_fixtures
+    
+    # Заменяем функцию install на вашу кастомную версию
+    install_fixtures.install = custom_install
+    
+    frappe.logger().info("Custom install function has been applied via monkey patching")
\ No newline at end of file