Opening Facebook profile via C#

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C#

HTTP

WebResponse

Hello guys.

I am under some serious headaches why some profiles that I want to "open" in my app.
When I open them I get message that the page is not present, when I open it in browser and works perfectly.

Could you give me advise how to rework the code piece?

What I have tried:

Here is what I have tried. This is existing profile but when I open it with this code does not.

Uri profileUri = new Uri(@"https://www.facebook.com/roger");
           
            HttpWebRequest httpWebRequest = (HttpWebRequest) WebRequest.Create(profileUri);

            httpWebRequest.Method = WebRequestMethods.Http.Get;
            httpWebRequest.Proxy = null;
            httpWebRequest.UserAgent = "Mozilla/5.0 (Windows NT 6.1) AppleWebKit/535.2 (KHTML, like Gecko) Chrome/15.0.874.121 Safari/535.2";
            httpWebRequest.AllowWriteStreamBuffering = true;
            httpWebRequest.ProtocolVersion = HttpVersion.Version11;
            httpWebRequest.AllowAutoRedirect = true;
            httpWebRequest.KeepAlive = false;
            httpWebRequest.ContentType = "text/html";
            httpWebRequest.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8";

            using (HttpWebResponse response = (HttpWebResponse)httpWebRequest.GetResponse())
            using (StreamReader sr = new StreamReader(response.GetResponseStream()))
            {
                
                source = sr.ReadToEnd();
            }