Follow these suggestions to fix the issue with the Microsoft Authenticator app for not displaying code. If the Microsoft account for the concerned user has expired or got deleted somehow ...

If you have an outdated carrier plan, your device may not receive messages ... a verification code anymore. Instead, Microsoft will send a prompt to the Authenticator app on your smartphone ...

If you’re backing up your authenticator app data, you can attempt to recover it. If not, to log in you’ll have to use a backup code or an alternate form of 2FA, if you set one up. Passkeys are ...