void OnFullscreenViewed()
{
// If we reach this stage, it means the user viewed the Ad past the initial screen.
// This could be a good point to reward the user (eg. give an in-game bonus item).
// You can also start reloading the Ad here if you are not using built-in auto reloading.
Debug.Log("AD Viewed\n");
fullscreenAd.ReloadAd();
}