How to use ad mob ad

I am new in Niotron, I used other network from last three years,
Here in Niotron I am unable to show any Admob Ad,

I create one app and publish it in to Google Play Store, My app Successfully published, But in my app Ad Does not show, In test mob Ad showing but in real time it is not show.

I used App ID from Ad Mob

Please Guide me !