Fix serializer when player id is missing

games/serializers.py

@@ -215,7 +215,7 @@ def check_field(field, default=None, new_value=DEFAULT):
                 if player_id == -1:
                     try:
                         data["player_ids"][i] = User.objects.get(
-                            username_iexact=player_name
+                            username__iexact=player_name
                         ).id
                     except User.DoesNotExist:
                         raise serializers.ValidationError(