Can't register application on Instagram

Question

I am writing C# client for Instagram. I've registered my application and filled the fields: Application Name, Description, Website, OAuth redirect_uri. But I receive this error message in my C# client:

This client is not xAuth enabled.

I think the problem is in Website, OAuth redirect_uri fields. What values must I put in these fields?

Here is method that have to get access_token (HttpRequest class from xNet library):

private string GetAccessToken()
        {
            using (var request = new HttpRequest())
            {
                var urlParams = new RequestParams();

                urlParams["client_id"] = "ce3c76b914cb4417b3721406d7fe3456";
                urlParams["client_secret"] = "b8ad0c21ce8142d0a8c0fa2d2bd78f53";

                urlParams["username"] = this.login;
                urlParams["password"] = this.password;
                urlParams["grant_type"] = "password";
                urlParams["scope"] = "comments likes relationships";

                try
                {

                    this.json = request.Post("https://api.instagram.com/oauth/access_token", urlParams).ToString();

                    var values = JsonConvert.DeserializeObject<InstagramResponse>(this.json);



                    return values.access_token;
                }
                catch (Exception)
                {
                    return null;
                }
            }
        }