Today I’ve received this email from Google Admob:
Ensure that you adopt SDKs which support app set ID
We noticed that you have not adopted app set ID for your apps.
Last July, Google Play announced advertising ID policy changes to help boost security and privacy. These changes have started to come into effect from April 1, 2022.
App set ID offers a privacy-friendly way to correlate usage or actions across a set of apps owned by the same organization when the advertising ID is unavailable. To support reporting and fraud prevention of opt-ed out users, Google AdMob recommends taking 20.5.0+ GMA SDK or later which support app set ID. After which, no further action is required.