I am using Xamarin.Auth For Authenticate user. I want to Authenticate Facebook User..Please check i have defined scope in code true or not.
My code for Authenticate given Below:

var auth = new OAuth2Authenticator (clientId: App.Instance.OAuthSettings.ClientId, 
                                    ****scope: "publish_stream,user_about_me,read_stream,email",** **
                                        authorizeUrl: new Uri (App.Instance.OAuthSettings.AuthorizeUrl), 
                                        redirectUrl: new Uri (App.Instance.OAuthSettings.RedirectUrl)); 
            auth.Completed += (sender, eventArgs) => 
            {
                if (eventArgs.IsAuthenticated)
                {
                    App.Instance.SuccessfulLoginAction.Invoke();
                    // Use eventArgs.Account to do wonderful things
                    App.Instance.SaveToken(eventArgs.Account.Properties["access_token"]);
                }
                else
                {

  `                  // The user cancelled
                }
            };

Please Help me Solve this Issue. i have attached image . please tell me what i missing.Thanks in Advance.