import static io.github.cdimascio.japierrors.ApiError.badRequest;
// ...

throw notFound();
throw badRequest("id required.");
throw internalServerError(exception);
// ...

// Create an api error creator
public class MyApiErrorCreator implements IApiErrorCreator {
    @Override
    public ApiError create(HttpStatus status, String message) {
        return new MyApiError(message);
    }
    @Override
    public ApiError create(HttpStatus status, Throwable t) {
        return new MyApiError(t.getMessage());
    }
}

// Create a custom api error object
// Add Json ignore properties (see source code link above)
public class MyApiError extends ApiError {
  @JsonProperty
  private String message;
  
  MyApiError() {
      super();
  }
  
  MyApiError(String message) {
    this.message = message;
  }
  
  public String getMessage() {
    return message;
  }
}