mormot service method returns base64 string on Lazarus

sample.pas

type
  TNotebook = packed record
    ID: TID;
    Title: RawUTF8;
    GUID: RawUTF8;
    CurrentNote: TID;
    procedure LoadFromObj(OrmNotebook: TOrmNotebook);
  end;

  TNotebookArray = array of TNotebook;

function TNotebookService.List(var Notebooks: TNotebookArray):
    TServiceCustomStatus;
var
  i: Integer;
  Results: TObjectList;
begin
  Result := HTTP_SUCCESS;
  Results := Self.Server.Orm.RetrieveList(TOrmNotebook,
    'UserId = ?', [GetUserId], '');
  try
    if Results <> nil then
    begin
      for i := 0 to Results.Count - 1 do
      begin
        SetLength(Notebooks, Length(Notebooks) + 1);
        Notebooks[I].LoadFromObj(Results[i] as TOrmNotebook);
      end;
    end;
  finally
    if Results <> nil then
      Results.Free;
  end;
end;

// Similar results with below method on the Server:
procedure TSampleServer.ListNotebooks(Ctxt: TSQLRestServerURIContext);
var
  Json: RawUTF8;
  Notebooks: TNotebookArray;
begin
  GetNotebooks(Notebooks);

  Json := DynArraySaveJson(Notebooks, TypeInfo(TNotebookArray));
  Ctxt.Returns(Json);
end;