The app I use shows google_mobile_ads on a test device but shows no ads on a real device.
Moreover, it shows this in logs on real device
I/flutter (14971): Failed to load a banner ad: No ad config.
I found some person said that you must publish the application on the store and then download it on your device, and the ads will appear.
Is it true? Is the app must be published before the ads will be shown?
p.s. when using firebase_admob I facing the same issue - on a real device in prod it shows no ads but works with test device, so maybe the issue lays somewhere deeper?
No, you don't need to upload to the store, you can add test device from Admob panel or use test ids to view ads, please review the document.