procedure TForm1.Button1Click(Sender: TObject);
var
LoginData, Response: TStringList;
error_text, name, rep: string;
///Headers:TIdheaderList ;
 //SSLHandler : TIdSSLIOHandlerSocketOpenSSL;
begin
 //HTTP:= TIdHTTP.Create(Application);
/////SSLHandler:= TIdSSLIOHandlerSocketOpenSSL.Create(HTTP);
////HTTP.IOHandler:= SSLHandler;
////SSLHandler.SSLOptions.Mode:= sslmClient;
////SSLHandler.SSLOptions.Method := sslvSSLv3;

LoginData := TStringList.Create;
Response := TStringList.Create;
 idHTTP1.Request.CustomHeaders.Add('Upgrade-Insecure-Requests: 1');
try
  IdHTTP1.Request.UserAgent := 'Mozilla/5.0 (Windows NT 6.1; rv:54.0) Gecko/20100101 Firefox/54.0';
 IdHTTP1.Request.Host := 'www.parimatch.com ' ;
   IdHTTP1.Request.ContentType:=' application/x-www-form-urlencoded'  ;
    IdHTTP1.Request.Referer:= 'https://www.parimatch.com/?login=1';///?login=1';
    IdHTTP1.Request.Connection:='keep-alive';
    IdHTTP1.Request.AcceptLanguage:='ru-RU,ru;q=0.8,en-US;q=0.5,en;q=0.3';
    IdHTTP1.Request.AcceptEncoding:= 'gzip, deflate';
      //IdHTTP1.Request.Headers.Add("Upgrade-Insecure-Requests","1");
   // idHTTP1.Request.CustomHeaders.Add('Upgrade-Insecure-Requests: 1');

   LoginData.Add('qt=dd84221f4e9f08715063238f07130f6c');
  LoginData.Add('username=' + Edit1.Text);
  LoginData.Add('passwd=' + Edit2.Text);

  //LoginData.Add('a=2');
  //LoginData.Add('ajax=1');
  //LoginData.Add('rnd=218');
  //LoginData.Add('_tp_=xml');
  Response.Text := IdHTTP1.Post('https://www.parimatch.com/?login=1 ', LoginData);
  Memo1.Lines.Add(Response.Text);

  Memo1.Lines.Add('Авторизация успешна!');
  

except
    on E : Exception do
      begin showmessage('Error: '+E.Message);
      Memo1.Lines.Add('Ошибка в работе программы');
      end;
  end;