How to test interstitial admob viability before admob has approved the new app

I am creating a quiz using Thunkable. I would like for whenever a user clicks on option D for an ad to appear. I have placed what I believe to be the correct blocks in place to make this happen.

Admob has not yet approved my addition of this new app. How can I know inside of Thunkable if the admob functionality is working? Thanks