nologin - politely refuse a login
First check nologin exists in /etc/shells $ cat /etc/shells if nologin is not found then append # echo "/usr/sbin/nologin" >> /etc/shells
To set a user’s shell to nologin # usermod <username> -s /sbin/nologin # usermod ilugc -s /sbin/nologin
regards, T.Dhanasekar