Note : Do Not Copy The Hash (#)
# sudo apt update && sudo apt upgrade
# sudo apt install openssh-server
# sudo systemctl enable --now ssh
# sudo systemctl status ssh
#sudo systemctl disable ssh
#ssh username@IP_address / ssh username@domain
Backup the file
#sudo cp /etc/ssh/sshd_config /etc/ssh/sshd_config.initial
#sudo nano /etc/ssh/sshd_config
PubkeyAuthentication yes
PermitRootLogin yes
#sudo systemctl restart ssh
#ssh -p port_number username@IP_address