finish payment logic

backend/order/admin.py

@@ -42,10 +42,21 @@ class BankRecordInline(StackedInline):
         return [field.name for field in self.model._meta.fields]
 
 
+class CartItemInline(StackedInline):
+    model = CartItem
+    extra = 0
+    max_num = 0
+
+    def has_delete_permission(self, request, obj=None):
+        return False
+    
+    def has_add_permission(self, request, obj=None):
+        return False
 
 @admin.register(Cart)
 class CartAdmin(ModelAdmin):
-    pass
+    inlines = [CartItemInline]
+