Each add-on's interface will be different, varying by developer and app functionality. However, in the actual menu the add-on appears in, there are a few options.
Reload - If something isn't working right or you just want to reload your add-on, hit this button.
Info - Open this menu to reveal information about an add-on's developer, version number, support link, and nuken Shop listing information. You can also directly support the developer via their donation link.
Pin - Pretty self-explanatory. Pin the add-on to your workspace, allowing you to drag it around where you'd like. You can also minimize a pinned add-on, to keep it out of the way until you need it back.
If the developer supports it, you can also adjust this add-on's size by dragging horizontally from the bottom right corner.