How to use build runner with freezed for specific folder?

[Trung15010802]

I tried dart run build_runner build --build-filter=lib\model*.dart But it has an error.

* Use `JsonConverter`
  https://pub.dev/documentation/json_annotation/latest/json_annotation/JsonConverter-class.html
* Use `JsonKey` fields `fromJson` and `toJson`

[Trung15010802]

I upgraded the lasted version of freezed.