Hello Jose Luis Gonzalez, unfortunately the Microsoft Authenticator app does not currently support changing the backup email account directly within the app without reinstalling it. The backup email address is tied to the account used during the initial setup, and changing it requires a fresh setup. As a result, here's what you need to do.
- Open the Authenticator app, go to Settings and select Backup. Ensure that your current data is backup to your Yahoo email address.
- Uninstall the Authenticator app from your phone and reinstall the app from Google Play Store.
- Open the reinstalled Authenticator app and sign in with your Gmail account.
- Import your backup here
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