Changing The Layout For A Page That Exists But Does Not Appear In The Layout Editor

I would like to edit my 'account registration page', which was pre-made when I bought my software and looks nice but I want to make a few tweaks. The problem is that I don't see it in the list of layouts on my layout editing page- there is a chance I may have accidentally deleted the layout page for it a while ago. Any ideas on how I can get it back/ edit this page? The url that's showing up is myurl/profiles-add.

Create new layout page manually. Use the profiles.add value for Dispatch field