We shouldn't stop there. Now that we have access to a user with sudo privileges, we don't need to log in as root anymore. Therefore, we should disable root login through another configuration entry in the sshd_config.
Find the PermitRootLogin entry and set that to no:
PermitRootLogin no
Reload the SSH daemon to ensure that this change takes effect:
root@hobnob:# systemctl reload ssh.service
Now, from your local machine, try to log in as root; you should get an error:
$ ssh root@142.93.241.63Permission denied (publickey).