How do I add/remove DownThemAll filters?

I was trying to add a new filter but I guess I didn’t fill it out properly and all it added to my “Make Your Selection” filter list is “New Filter” (but not to the “Filters” list in preferences") so I tried again and again it just added “New Filter” that doesn’t seem to do anything.

So how do I add filters? Is there some specific code I have to use? Also how do I remove filters from the “Make Your Selection” window, I can’t find the addon in the profile and uninstalling/reinstalling it doesn’t remove the new filters.

You can contact the developers using the support information provided in the add-on page.