Joel's Opinionated Guide to GPG and SSH on the YubiKey
A long time ago I got a (YubiKey 5C Nano)[https://support.yubico.com/hc/en-us/articles/360013724699-YubiKey-5C-Nano], and didn’t use it. All the noise around Passkeys made me decide to get it out, which was a waste of time because Linux support for Passkeys doesn’t yet exist. But they can be used for FIDO and as a GPG smartcard.