freezed jsonがスネークケースの場合の指定

@freezed
class AuthRequest with _$AuthRequest {
  const factory AuthRequest(
      {@JsonKey(name: 'user_name') required String name,
      @JsonKey(name: 'password') required String password}) = _AuthRequest;

  factory AuthRequest.fromJson(Map<String, dynamic> json) =>
      _$AuthRequestFromJson(json);
}