It seems like it's only available on the Yubikey 5 Series https://support.yubico.com/hc/en-us/articles/360016649319-YubiKey-5-2-3-Enhancements-to-FIDO-2-Suppor

It seems like it's only available on the Yubikey 5 Series https://support.yubico.com/hc/en-us/articles/360016649319-YubiKey-5-2-3-Enhancements-to-FIDO-2-Support https://support.yubico.com/hc/en-us/articles/360016649319-Yu...