fix: Add mandatory depends on condition for export type field
diff --git a/erpnext/patches.txt b/erpnext/patches.txt
index 86356e3..0fc50c5 100644
--- a/erpnext/patches.txt
+++ b/erpnext/patches.txt
@@ -296,7 +296,7 @@
 erpnext.patches.v13_0.update_amt_in_work_order_required_items
 erpnext.patches.v12_0.show_einvoice_irn_cancelled_field
 erpnext.patches.v13_0.delete_orphaned_tables
-erpnext.patches.v13_0.update_export_type_for_gst
+erpnext.patches.v13_0.update_export_type_for_gst #2021-08-16
 erpnext.patches.v13_0.update_tds_check_field #3
 erpnext.patches.v13_0.add_custom_field_for_south_africa #2
 erpnext.patches.v13_0.shopify_deprecation_warning
diff --git a/erpnext/patches/v13_0/update_export_type_for_gst.py b/erpnext/patches/v13_0/update_export_type_for_gst.py
index 478a2a6..3e20212 100644
--- a/erpnext/patches/v13_0/update_export_type_for_gst.py
+++ b/erpnext/patches/v13_0/update_export_type_for_gst.py
@@ -8,11 +8,19 @@
 	# Update custom fields
 	fieldname = frappe.db.get_value('Custom Field', {'dt': 'Customer', 'fieldname': 'export_type'})
 	if fieldname:
-		frappe.db.set_value('Custom Field', fieldname, 'default', '')
+		frappe.db.set_value('Custom Field', fieldname, 
+			{
+				'default': '',
+				'mandatory_depends_on': 'eval:in_list(["SEZ", "Overseas", "Deemed Export"], doc.gst_category)'
+			})
 
 	fieldname = frappe.db.get_value('Custom Field', {'dt': 'Supplier', 'fieldname': 'export_type'})
 	if fieldname:
-		frappe.db.set_value('Custom Field', fieldname, 'default', '')
+		frappe.db.set_value('Custom Field', fieldname, 
+			{
+				'default': '',
+				'mandatory_depends_on': 'eval:in_list(["SEZ", "Overseas"], doc.gst_category)'
+			})
 
 	# Update Customer/Supplier Masters
 	frappe.db.sql("""
diff --git a/erpnext/regional/india/setup.py b/erpnext/regional/india/setup.py
index b4f146c..2d6b913 100644
--- a/erpnext/regional/india/setup.py
+++ b/erpnext/regional/india/setup.py
@@ -642,7 +642,8 @@
 				'fieldtype': 'Select',
 				'insert_after': 'gst_category',
 				'depends_on':'eval:in_list(["SEZ", "Overseas"], doc.gst_category)',
-				'options': '\nWith Payment of Tax\nWithout Payment of Tax'
+				'options': '\nWith Payment of Tax\nWithout Payment of Tax',
+				'mandatory_depends_on': 'eval:in_list(["SEZ", "Overseas"], doc.gst_category)'
 			}
 		],
 		'Customer': [
@@ -660,7 +661,8 @@
 				'fieldtype': 'Select',
 				'insert_after': 'gst_category',
 				'depends_on':'eval:in_list(["SEZ", "Overseas", "Deemed Export"], doc.gst_category)',
-				'options': '\nWith Payment of Tax\nWithout Payment of Tax'
+				'options': '\nWith Payment of Tax\nWithout Payment of Tax',
+				'mandatory_depends_on': 'eval:in_list(["SEZ", "Overseas", "Deemed Export"], doc.gst_category)'
 			}
 		],
 		'Member': [