Sehr schön, #ssh ohne #Yubikey:

❯ ssh ionos
Confirm user presence for key ED25519-SK SHA256:8w5Nw+rD5ofG5ioJQtEjQRQm5GgfPnjnm7u1dPI+UwM
sign_and_send_pubkey: signing failed for ED25519-SK "/Users/rainer/.ssh/yubikey-ionos": device not found
root@74.208.189.173: Permission denied (publickey).

Yubikey anstöpseln, bei Prompt die kleine Metallplatte berühren:

❯ ssh ionos
Confirm user presence for key ED25519-SK SHA256:8w5Nw+rD5ofG5ioJQtEjQRQm5GgfPnjnm7u1dPI+UwM
User presence confirmed
Linux ionos 5.10.0-23-cloud-amd64 #1 SMP Debian 5.10.179-1 (2023-05-12) x86_64