[Delphi Rio] How to close current pdf i show.

unit Unit1;

interface

uses

  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,

  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.OleCtrls, AcroPDFLib_TLB,

  Vcl.StdCtrls;

type

  TForm1 = class(TForm)

    acrpdf1: TAcroPDF;

    btn1: TButton;

    btn2: TButton;

    procedure btn1Click(Sender: TObject);

  private

    { Private declarations }

  public

    { Public declarations }

  end;

var

  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);

begin

     acrpdf1.src:=GetCurrentDir+'\assets\dokumen\welcome.pdf';

     acrpdf1.Show;

end;

end.

when I close the application I got force close. so before I close my application, I want to release the adobe reader 1st.

or any recommendation to do that?

my question is how to do that, there is no such function to do that.