Moving Microsoft Authenticator MFA App to a New Mobile Device
If you have Microsoft Authenticator set up on a device and need to move it, Microsoft has articles on how to do this for both Apple (iOS) and Android.
Back up account credentials in Microsoft Authenticator - https://support.microsoft.com/en-us/account-billing/back-up-account-credentials-in-microsoft-authenticator-bb939936-7a8d-4e88-bc43-49bc1a700a40
Restore account credentials from Microsoft Authenticator - https://support.microsoft.com/en-us/account-billing/restore-account-credentials-from-microsoft-authenticator-ce53096e-1e1c-4840-9e32-1618bc33cd43