Open server console and login as root user, or open SSH and login as an existing user with root privileges

Open the SSH configuration file using a text editor:
nano /etc/ssh/sshd_config

Find the line '#Port 22' or 'Port 22', uncomment it by removing the hash, and change 22 to your preferred port number (e.g., 2222). Save and close the file.

If you have a firewall enabled, allow the new port:
ufw allow 2222/tcp

Restart the SSH service to apply the changes:
systemctl restart ssh

If you have Premium OS support from us, we can configure the Firewall for you.