Unity Game iOS Ad Issue Fix

I have a Unity-developed game with an AdMob integration, which is running ads on Android but failing to serve any on iOS. The SDK is confirmed to be correctly integrated, with the only log message being 'No ad available'. I need an experienced professional to quickly connect to my Mac OS computer and troubleshoot the issue.

Ideal skills would include:
- Proficiency in Unity
- Experience with AdMob
- Knowledge of iOS debugging
- Ability to work under time pressure

I would appreciate a swift resolution to this problem. Thank you.