Admob gives advertising error

A required meta-data tag in your app's AndroidManifest.xml does not exist. You must have the following declaration within the element:
Not: 5 saniye boyunca bildirilen başka bir hata görmezsiniz.

What happens may depend on which extension you use to provide the service. The extensions are created by third parties, not App Inventor.

You might contact the developer of your extension... Search results for 'admob' - MIT App Inventor Community lists several possibilities. If you paid for your extension, ask the developer for help please.

Appinventor prepared when we did not use?
We were in need of absence.