Facebook sharing result problem

my code adding coins if Facebook share result is success ... it's working good on unity when testing .. but after building the app and testing it on android share goes well but with no adding any coins

 private void OnShare(IShareResult result){
         if (result.Cancelled || !string.IsNullOrEmpty (result.Error)) {
         } else if (!string.IsNullOrEmpty (result.PostId)) {
         } else  {
             if (gameObject.name == "ShareFree") {
                 Coins = Coins+4; }
                              }
               }