To authenticate your account again after your friend's authenticator app has been uninstalled, you can follow these steps:
- Use a Backup Method: If you have set up any backup authentication methods (like email or SMS), try using those to regain access to your account.
- Reinstall Authenticator: You can download the Microsoft Authenticator app on your device. Once installed, you will need to add your account back into the app. This typically requires you to sign in with your credentials or use a recovery code if you have one.
- Contact Support: If you cannot access your account through backup methods or the Authenticator app, consider reaching out to Microsoft support for assistance in recovering your account.
Make sure to set up your own authenticator app to avoid similar issues in the future.