If you have just setup VPS (i.e ubuntu 20.04 or any) and want to add new user with its own SSH key, then do:
username=myuser adduser $username usermod -aG sudo $username sshDir=/home/$username mkdir -p $sshDir/.ssh touch $sshDir/.ssh/authorized_keys chmod -R go= $sshDir/.ssh # idk, if this is needed: chown root:root $sshDir/ chown -R $username:$username $sshDir/ chmod 644 $sshDir/.ssh/authorized_keys chmod 700 $sshDir/.ssh
next, add the ssh public key (ssh-rsa .....) in authorized_keys file on new line:
nano $sshDir/.ssh/authorized_keys
That’s all.
If you want to be able to log in as the user with PASSWORD (without SSH key), then do:
nano /etc/ssh/sshd_config
find PasswordAuthentication and enable it
(if you forget password, reset it by: passwd $username )