When I try to use ssh-copy-id -i /root/.ssh/id_ed25519 root@192.168.134.140, it always returns Permission denied, please try again
I know that ssh-copy-id is a script in which scp and ssh is used. And scp to something like root@192.168.134.140 will fail. It makes sense to me.
But, after I unlocked the root user following the answer in this post: How to enable root login?, still it fails. Why is that and how can fix that: All I want is to ssh as a root user to 192.168.134.140 without password.