Facebook interstitial ads are not loaded anymore

i have monetize my app with facebook but facebook’s interstitial ads are not show anymore in my app. but the banner ads are load successfully in the app.
can anyone please help me to solve this problem.fb1 fb2

  1. Is your app in playstore?
  2. Has your app been approved by facebook
  3. How much traffic your app has?
  4. Is your app in long term review by facebook?