Сервер не доступен при отправке POST запроса - C#

static void Main(string[] args)
        {
            var request = (HttpWebRequest)WebRequest.Create("https://instagram.com/accounts/login/");
            request.Method = "POST";
            request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
            request.Host = "instagram.com";
            request.Referer = "https://instagram.com/accounts/login/";
            request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; rv:25.0) Gecko/20100101 Firefox/25.0";
            request.ContentType = "text/html; charset=utf-8";
            request.CookieContainer = new CookieContainer();
            request.CookieContainer.Add(Cooks);
            string data = "csrfmiddlewaretoken=ea58f04f19849c7c3ac32c212f27b06b&username=ilya29&password=665873877";
            request.ContentLength = data.Length;
 
            IAsyncResult getRequestStream = request.BeginGetRequestStream(null, null);
            var writer = new StreamWriter(request.EndGetRequestStream(getRequestStream));
            writer.Write(data);
            writer.Close();
 
            Console.WriteLine("Посылаем запрос");
            request.BeginGetResponse(OnAsyncCallback, request);
            Console.WriteLine("Запрос послан");
            Console.ReadKey();
        }
 
        private static void OnAsyncCallback(IAsyncResult asyncResult)
        {
            var httpWebRequest = (HttpWebRequest)asyncResult.AsyncState;
            WebResponse response = httpWebRequest.EndGetResponse(asyncResult);
            Console.WriteLine("ответ получен");
            var reader = new StreamReader(response.GetResponseStream());
            string str = reader.ReadToEnd();
            Console.WriteLine(str);
        }