I followed the documentation on firebase to complete the setup.

SDK Installation and Mediation Registration References https://developers.google.com/admob/android/mediation/meta

for registering a test user https://developers.facebook.com/docs/audience-network/setting-up/testing/platform#test-users

When testing with the ad checker, the no fill error kept occurring. I'm not sure what to do to fix it. Has anyone else had similar issues?

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