flutter google AdMob Ad failed to load : 1 I/flutter ( 8661): Failed to load an interstitial ad: Error building request URL

I'm trying to add google admob interstitial ad to my flutter application.

I used this tutorial https://codelabs.developers.google.com/codelabs/admob-ads-in-flutter#3 and did exactly the same.

I requested approval for my admob account and got approved. I requested approval for my iOS and android app and still waiting for approval.

on both android and flutter I get the same errors :

I/Ads ( 8661): This request is sent from a test device.
I/Ads ( 8661): Ad failed to load : 1
I/flutter ( 8661): Failed to load an interstitial ad: Error building request URL.

for the app id I use this real app id from the admob site:

I mention the app id in the AndroidManifest.xml and Info.plist.

For the unit id, I tried the real one from the google admob site and the test one from this link: https://developers.google.com/admob/android/test-ads and https://developers.google.com/admob/ios/test-ads. of course non of them worked and still the same error.

What am I doing wrong? and why flutter can't build the http request? I followed exactly the tutorial.

The problem resolved by google team at that github