Manage your YubiKey via the YubiKey manager application (Reset Security PIN)

The YubiKey manager installation file is found here, choose the correct download file for your Operating System.

If you have forgotten your Hardware Token Security PIN, the Yubikey Manager desktop software lets you to Reset your PIN (restore it back to default). The Hardware Token can then be set up again via your Microsoft account

Open the YubiKey Manager application and insert your YubiKey

Click on the Applications tab and choose Fido2

Now you have 2 options, Change the Pin or Reset (Restore defaults) this will wipe all FIDO credentials.

To restore to Default, click Restore FIDO and click Yes to Confirm

You will be instructed to remove and insert your YubiKey Hardware Token

And finaly to Touch the Sensor on your YubiKey to complete the process