I am trying to add a use to wheel group using in a Ubuntu server.

sudo usermod -aG wheel john

I get:

usermod: group 'wheel' does not exist

On my /etc/sudoers I have this:

>  cat /etc/sudoers
> # sudoers file.
> #
> # This file MUST be edited with the 'visudo' command as root.
> #
> # See the sudoers man page for the details on how to write a sudoers file.
> #
> 
> # Host alias specification
> 
> # User alias specification
> 
> # Cmnd alias specification
> 
> # Defaults specification
> 
> # User privilege specification root    ALL=(ALL) ALL %root   ALL=(ALL) NOPASSWD: ALL
> 
>     %wheel  ALL=(ALL) NOPASSWD: ALL

Do I have to do groupadd of wheel?