Instagram api server-side authentication asp.net mvc

Question

I'm trying to realize server-side authentication by example in IG docs, but get a trouble. When I'm doing my request, I've getting response with status 302 Found, and in Headers Location I haven't new redirect url with code, but if I do same things in browser, all ok.

Here is my code and examples:

public JsonResult InstagramTeaser()
    {
        try
        {
            var clientId = Configuration.AuthKeys.InstagramOAuthClientId;
            var clientSecret = Configuration.AuthKeys.InstagramOAuthClientSecret;
            var redirectUrl = "http://localhost";
            var uri = $"http://api.instagram.com/oauth/authorize/?client_id={clientId}&redirect_uri={redirectUrl}&response_type=code";
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uri);
            request.AllowAutoRedirect = false;
            string redirUrl = String.Empty;
            using (HttpWebResponse response = (HttpWebResponse) request.GetResponse())
            {
                int status = (int)response.StatusCode; // 302 Found
                redirUrl = response.Headers[HttpResponseHeader.Location]; // And here I'm getting my old uri
            }

            return Json(redirUrl, JsonRequestBehavior.AllowGet);
        }
        catch (Exception e)
        {
            return Json(e.Message, JsonRequestBehavior.AllowGet);
        }
    }

Results in browser

Answer 1

The way auth works in MVC is that when you aren't logged in and try to access a secure page it throws a 401 exception. MVC then catches this exception and redirects the user to the login page (which is the 302 you are seeing)

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