Authenticate login API with user_login.

Co-authored-by: Cursor <cursoragent@cursor.com>

backend/apps/accounts/views.py

@@ -235,7 +235,7 @@ class LoginView(APIView):
         serializer.is_valid(raise_exception=True)
         user = authenticate(
             request,
-            username=serializer.validated_data["user_name"],
+            username=serializer.validated_data["user_login"],
             password=serializer.validated_data["password"],
         )
         if user is None: