[Pas2js] is it possible to create GUi with no need to manually add the code to .html page

[Mgr. Janusz Chmiel]

Here is my wrong code.

program Project1;

{$mode objfpc}

uses
  browserapp, JS, Classes, SysUtils, Web, webwidget;

type
  TMyApplication = class(TBrowserApplication)

    procedure doRun; override;
  end;

procedure TMyApplication.doRun;

begin
  FMyPage:=TWebPage.Create(Self);
FMyButton:=TButtonWidget.Create(Self);
FMyButton.Parent:=FMyPage;
FMyButton.Text:='Start The code';


  Terminate;
end;

var
  Application : TMyApplication;

begin
  Application:=TMyApplication.Create(nil);
  Application.Initialize;
  Application.Run;
  Application.Free;
end.
I Am getting The following error
project1.lpr(17,3) Error: identifier not found "FMyPage"
But where to declare The variable FMyPage and which data type should I
assign it?