Key Based Authentication

mkdir -p $HOME/.ssh
chmod 0700 $HOME/.ssh

Put public key into .ssh/authorized_keys

sed -i 's/#PasswordAuthentication yes/PasswordAuthentication no/g' /etc/ssh/sshd_config
sed -i 's/#Port 22/Port 2222/g' /etc/ssh/sshd_config

scp

scp .ssh/id_ed25519.pub pve:/root/.ssh

ssh-add

ssh-add ~/.ssh/id_ed25519