unit Unit1;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants,
  System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, IdBaseComponent, IdComponent,
  IdTCPConnection, IdTCPClient, IdHTTP, Vcl.StdCtrls;

type
  TForm1 = class(TForm)
    Memo1: TMemo;
    IdHTTP1: TIdHTTP;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
var
  cmd : string;
begin
  IdHTTP1.Request.CustomHeaders.Clear;
  IdHTTP1.Request.CustomHeaders.AddValue('Accept', 'application/vnd.twitchtv.v5+json');
  IdHTTP1.Request.CustomHeaders.AddValue('Client-ID', 'gs7pui3law5lsi69yzi9qzyaqvlcsy');
  cmd := 'https://api.twitch.tv/kraken/videos/370746236';
  Memo1.Lines.Text := IdHTTP1.Get(cmd);
end;

end.