MFA User cannot access Mobile Phone e.g. lost phone (work around)
 One-time bypass  is the solution:  The one-time bypass feature allows a user to authenticate a single time without performing two-step verification. The bypass is temporary and expires after a specified number of seconds.  In situations where the mobile app or phone is not receiving a notification or phone call, you can allow a one-time bypass so the user can access the desired resource.   Create a one-time bypass   S ign in to the Azure portal as an administrator.  https://portal.azure.com   Browse to Azure Active Directory > MFA Server > One-time bypass .  Select Add . If necessary, select the replication group for the bypass. Enter the username as username@domain.com . Enter the number of seconds  that the bypass should last. Enter the reason  for the bypass. Select Add .  The time limit goes into effect immediately.  The user needs to sign in before the one-time bypass expires.    View the one-time bypass report Sign in to the Azure portal. Browse to Active Directory ...