How do I add topics to my profile?

Just looked at my profile and I don’t see a way to add. You can remove or make private the ones you have but I don’t see an add function. They were mainly used to feed you questions in the “just for you” category which doesn’t work either but they’re also nice when you want to see what someone else is interested in.

Using my desktop PC:

If I hover my pointer over a topic button, I get a drop-down balloon that gives me the option to “Add Topic”.

This happens regardless of where the button is located: a question, another user’s profile, or the “Popular topics” block on each section page.

If one wants to add a topic that doesn’t exist, I guess one could create a question and include that topic, and add it from there.

However, I don’t see any way to add a topic on my profile’s Topics page.
I.e., there’s no link nor are there any directions to add one on that page, that I can see.