ALL USERS. See these best practices for configuring Azure Multifactor Authentication.
Authenticator App number matching is one of the options you can use to verify your identity when logging in to ECU resources.
Set up and manage your ECU account authentication methods
Set up phone call verification as the authentication method for your PirateID user account.
Set up the Authenticator mobile app as your default two-factor account verification method.
Set up text message as the authentication method for your PirateID user account.