Has the plugins/files tabs been removed?

Above is a screenshot of the server main page. I've been through multiple tabs, and can't seem to find the plugins or files tabs. Both the tutorials (the one from 2015 on the forums, and 2017 on YouTube) haven't helped, since they seem to be out of date. There are a few plugins I was hoping to put on my server, so I'd like to find out what's going on soon.

Thanks.

Thank you. I just glanced over that in the tutorials since it seemed like they meant any software. My fault, I suppose.