In this video, you’ll learn how to re-register a new phone using the Microsoft Authenticator app.
Once the two-factor security has been set up for your Office 365 work account you may receive a push notification from the authenticator app asking you to approve the login. One you approve you can access your Office 365 account. Or, you may be asked to provide a 6-digit code from the Authenticator app.
Links in video: https://aka.ms/mysecurityinfo