uses
  httpsend, ssl_openssl;

procedure TForm1.Button1Click(Sender : TObject);
var
  HTTP : THTTPSend;
  FPostData : string;
begin
  HTTP := THTTPSend.Create;
  with HTTP do
  begin
    Protocol := '1.1';
    KeepAlive := True;
    UserAgent := 'Opera/9.80 (Windows NT 6.1; U; pl) Presto/2.7.62 Version/12.16';
    Clear;
    MimeType := 'application/json'; //'application/x-www-form-urlencoded';
    HTTP.HTTPMethod('GET', 'https://e-skok.pl/eskok/login.jsp');
    {
    FPostData := 'username=ogarnij&password=sie';
    Document.Write(PChar(FPostData)^, Length(FPostData));
    HTTP.HTTPMethod('POST', 'https://e-skok.pl/eskok/login.jsp');
    }
    Document.SaveToFile('D:\test.html');
  end;
  HTTP.Free;
  ShowMessage('Done');
end;