If “Emergency Logon” is allowed by your organization’s settings, you can log on to your Mac using only your password, without FIDO authentication, within a certain period of time.
This is a mechanism that allows you to log on with only your password, within a period allowed by your organization, even in situations where FIDO authentication cannot be performed, such as when a security key is lost or broken.

Whether emergency logon is available, and for how long, depends on your organization’s settings. Please contact your organization’s administrator for details.