failed to load ad : 3

Question

I\'m setting an ad to my Android application using DoubleClick and can\'t manage to show the final ad, can someone help me?

When I test an ad by adding ".addTest

Answer 1

I've made the stupidest error. Passed app id into MobileAds.initialize from one app and used placement id in loadAd from another admob app.

Once I corrected placement id all come to work.