อยากทราบแนววิธีการเขียน http request โดยใช้ proxy ครับ

private void button1_Click(object sender, EventArgs e)
        {
            string[] proxyIP = textBox2.Text.Split(':');
            string MyProxyHostString = proxyIP[0];
            int MyProxyPort =  Convert.ToInt32(proxyIP[1]);
            ServicePointManager.Expect100Continue = true;
            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
            HttpWebRequest request = WebRequest.Create(textBox1.Text) as HttpWebRequest;
            request.ProtocolVersion = HttpVersion.Version10; // fix 1
            request.KeepAlive = false; // fix 2
            request.Timeout = 1000000000; // fix 3
            request.ReadWriteTimeout = 1000000000; // fix 4
            request.Proxy = new WebProxy(MyProxyHostString, MyProxyPort);
            request.UserAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36";
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream receiveStream = response.GetResponseStream();

            WebBrowser webBrowser1 = new WebBrowser();
            webBrowser1.DocumentStream = receiveStream;
        }