Sidebar removal

Hi, this should be simple but I can’t figure out how to remove the sidebar from the above page. This is indirectly linked to a theme and yes, I have left them a few messages but they have been unresponsive. I feel like removing a sidebar should be easy but I’m stumped. Any suggestion would be appreciated. oh, how can I upload a screenshot? I don’t have a link to it.

The page I need help with: [log in to see the link]