Authentication Methods Policy: Users will need to be enabled for the Authenticator app and the Authentication mode set to Any or Push.MFA Registration Policy: Users will need to be enabled for Notification through mobile app.Admins need to enable users for the Authenticator app using one of these policies:.Users can't have already set up the Authenticator app for push notifications on their account.No additional license is needed for a registration campaign. Every edition of Azure AD includes Azure AD Multi-Factor Authentication. Your organization must have enabled Azure AD Multi-Factor Authentication.If a user taps Not now to snooze the app setup, they'll be nudged again on the next MFA attempt after the snooze duration has elapsed. In addition to choosing who can be nudged, you can define how many days a user can postpone, or 'snooze', the nudge. This allows targeted campaigns to move users from less secure authentication methods to the Authenticator app.

You can include or exclude users or groups to control who gets nudged to set up the app. Users will go through their regular sign-in, perform multifactor authentication as usual, and then be prompted to set up Microsoft Authenticator. You can nudge users to set up Microsoft Authenticator during sign-in.

Setup microsoft authenticator app