FIDO2 keys as a security method is available with Microsoft Azure AD for already a couple of years now. Being the most secure access method available for Office 365 user access, enrolling FIDO2 security keys had a requirement of MFA to be configured for the users, which made it useless for use cases where users do not have (or do not want) to use multiple devices to log in. This has finally changed!
During the MS Ignite 2021 conference (which was held virtually this year as well), in addition to GA of Passwordless, Microsoft also announced a new feature, Temporary Access Pass in Azure AD (Preview), which will allow your end users to use only a FIDO2 Security key to access their account (this eliminates the requirement of having the MFA configured prior to that, which was the case before).
The guide below will describe how the administrator can set Temporary Access Pass for a user, and how that user can subsequently enroll his/her FIDO2 security key