WooCommerce product variation usage

I obviously need a brain upgrade, as I can’t seem to find this anywhere.

I have created a product, an attribute and variations. I’ve added the attribute and some of the variation, created all varions, filled out the information for each variation, and published the product.

Now I find that I need to add another variation to that product from the list of variations. How?

I’ve tried the “Add new variation” option (which seemed to make sense) and it did create a new variation (named “Any variation”), but all it gave me to choose which variation I wanted was the choice of “Any variation” plus the variations I’d already added. And there’s no way to change “Any variation” to anything else.