YubiKey FIDO2 OpenSSH


I have been trying to configure FIDO2 SSH with a Brume2 (4.2 latest beta), roughly following these
Securing OpenSSH with FIDO2 | PrivSec - A practical approach to Privacy and Security
theymademeputsomethinghere: Windows, OpenSSH, and FIDO2 (girlboss.ceo)

I installed the openssh-server & libfido2 packages (the versions available support sk-ssh-ed25519), & disabled dropbear but I can’t seem to SSH at all afterwards. There is also no visible folder /root/.ssh/ when in WinSCP so I’m unsure as to whether I need to make one - but when I go to do so it warns me that this directory already exists. Powershell gives:

“root@brume2:~# ssh-add ~/.ssh/id_ed25519_sk
/root/.ssh/id_ed25519_sk: No such file or directory”

“PS C:\Users\NX.ssh> ssh -i id_ed25519_sk root@ -p 2222
root@’s password:” Password requirement still in sshd_config. No key requested since I assume it’s dropbear, logs in fine.

Does the id_ed25519_sk.pub file exist?
Can you share the complete command flow and execution results?