Consider this an evergoing brown study.

PowerShell: Enable/Enforce Multifactor Authentication for All (Bulk) Users in Office 365

Initial Setup MFA helps secure user sign-ins for cloud services beyond just a single password. With MFA for Office 365, users are required to acknowledge a phone call, text message, or app notification on their smart phones after correctly entering their passwords. They can sign in only after this second authentication factor has been satisfied…. Read more