private void RewardedCallback_AdFailedToShow(object sender, AdMobErrorEventArgs e)
 {
     OnRewardedVideoAdFailedToShow?.Invoke(sender, e);
 }
 private void InterstitialVideoAdListener_AdFailedToLoad(object sender, AdMobErrorEventArgs e)
 {
     OnInterstitialVideoFailed?.Invoke(sender, e);
 }