How do I add designs in the Topics section?

I have created 3 Topics in my shop and added 1 design each to test the Topics item. But now I can’t add any more designs to each Topic. I can add, and have added designs to the shop but I can’t seem to place them in a specific Topic. How do I do that?
All I can do is activate Topics On or Off, but I can’t add designs to a specific Topic. I can’t even add more Topics if I wanted to. Not that I want to at the moment (in the future I will be), but it’s pretty frustrating not being able to edit the Topics section. It’s not even possible to delete Topics or to edit them.
Am I missing or overlooking something here?

Replying to my own quesion: I found it!!
It’s in Settings - Page Settings. At the Start Page settings it can only be activated, but at the Page Settings it can be edited.