The file /etc/ssh/sshd_config is used to configure the SSH service. To allow root login with a password, modify the following lines in the Authentication section:
Change:
PermitRootLogin prohibit-password
to:
PermitRootLogin yes
And uncomment:
#PasswordAuthentication yes
to:
PasswordAuthentication yes
After altering the SSH configuration, the SSH service must be restarted to apply any changes made:
systemctl restart sshd.socket
To set a password for a user,
execute passwd <username> (e.g. passwd root for the default user root) and set your password. Then, execute the login command to log in the user with the new password.