Normally, your Microsoft Authenticator app will prompt you to enter a verification code when you are attempting to access a service that requires multifactor authentication (MFA). If the app does not prompt you for a code as expected, you can try refreshing the app using the directions below.

1) Open the Microsoft Authenticator app.

2) On the screen showing the list of accounts, swipe down and release. The screen will indicate that it's checking for notifications.

Outcome

If any notifications were found, you are prompted for verification as usual.