If you are running a Linux distro from inside your Chromebook you might have some issues accessing the right-click.
I am guessing this is because the Chromebook doesn’t have a right-click button per-say, just a contextual click by holding down alt when you click.
After much playing about with key combinations I found that using two fingers when you click on the button area will perform the same action as right-click.
Hopefully this will help someone else who is hopelessly trying to get a right-click menu up!