Guide to Using YubiKey for GPG and SSH
This is unnecessarily complicated to do for SSH, since SSH (and the Yubikey) support FIDO2:<p><a href="https://www.stavros.io/posts/u2f-fido2-with-ssh/" rel="nofollow">https://www.stavros.io/posts/u2f-fido2-with-ssh/</a>