After change, restart sshd unit (systemd)
Edit /etc/ssh/sshd_config

#AddressFamily any
AddressFamily inet

PermitRootLogin prohibit-password
#PermitRootLogin yes

PubkeyAuthentication yes
...
# To disable tunneled clear text passwords, change to no here!
PasswordAuthentication no
PermitEmptyPasswords no

 sudo sshd -T | grep -E '^(passwordauthentication|pubkeyauthentication)'