add coupon code on selling card of desk
diff --git a/erpnext/config/selling.py b/erpnext/config/selling.py
index 928bd5f..5db4cc2 100644
--- a/erpnext/config/selling.py
+++ b/erpnext/config/selling.py
@@ -127,7 +127,11 @@
 					"name": "Shipping Rule",
 					"description": _("Rules for adding shipping costs."),
 				},
-
+				{
+					"type": "doctype",
+					"name": "Coupon Code",
+					"description": _("Define coupon codes."),
+				}
 			]
 		},
 		{