App Invite not showing notification to friends in facebook

I'm having the same issue. My app is LIVE and PUBLIC on facebook, however, still no invitation seems to be sent out.

My code is: public void InviteFriends() { StartCoroutine(InviteFriendsRoutine()); }

 IEnumerator InviteFriendsRoutine() {
     if (!IsLoggined()) {
         Question.main.Ask(
                     LocalizationAssistant.main["question_invite_text"],
                     LocalizationAssistant.main["signin"],
                     LocalizationAssistant.main["cancel"]
                     );

         while (Question.main.Wait())
             yield return 0;

         switch (Question.main.GetResult()) {
             case 0: // Sign in
                 yield return StartCoroutine(Connection(true));
                 break;
             case 1: // Cancel
                 yield break;
         }
     }

     if (IsLoggined()) {
         FB.AppRequest(
             message: LocalizationAssistant.main["invite_text"],
             title: LocalizationAssistant.main["invite_title"]
         );
     }
 }

Do I miss sth here? Thanks.