C# HttpClientHandle

using System.Net;
using System.Net.Http.Headers;

CookieContainer cc = new CookieContainer();
var socketsHandler = new SocketsHttpHandler();
socketsHandler.AutomaticDecompression = DecompressionMethods.All;
socketsHandler.UseCookies = true;
socketsHandler.CookieContainer = cc;
socketsHandler.AllowAutoRedirect = true;
socketsHandler.MaxConnectionsPerServer = Math.Max(1, Environment.ProcessorCount - 1);
socketsHandler.PooledConnectionLifetime = TimeSpan.FromSeconds(60);
socketsHandler.PooledConnectionIdleTimeout = TimeSpan.FromMinutes(20);
socketsHandler.SslOptions.RemoteCertificateValidationCallback = (a, b, c, d) => true;
socketsHandler.UseProxy = false;
socketsHandler.Proxy = new WebProxy("socks5://127.0.0.1:8888");
socketsHandler.MaxAutomaticRedirections = 50;
socketsHandler.ResponseDrainTimeout = TimeSpan.FromSeconds(30);
var client = new HttpClient(socketsHandler);
client.DefaultRequestHeaders.UserAgent.TryParseAdd("Mozilla/5.0 XXXXXXXXXXXXXXXXXXXXXXXXXX");
client.DefaultRequestHeaders.Accept.TryParseAdd("text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9");
client.DefaultRequestHeaders.AcceptEncoding.TryParseAdd("gzip, deflate, br");
client.DefaultRequestHeaders.AcceptLanguage.TryParseAdd("zh-CN");
client.DefaultRequestHeaders.Pragma.TryParseAdd("no-cache");
client.DefaultRequestHeaders.CacheControl = new CacheControlHeaderValue {NoStore = true};
client.DefaultRequestHeaders.Add("Upgrade-Insecure-Requests", "1");
client.DefaultRequestHeaders.Add("Sec-Fetch-Site", "same-origin");
var html= "";
req.Content = new FormUrlEncodedContent(new[]
{
    new KeyValuePair<string, string>("email", us),
    new KeyValuePair<string, string>("passwd", pw),
    new KeyValuePair<string, string>("code", "")
});