How to list categories in reverse alphabetical order?

I am organising posts into sets of 10 comprising an “issue” of a very bloglike web “magazine”, using “issue1”, “issue2”, etc., as categories.

How can I list these categories on a sidebar widget in reverse alphabetical order, such that “Issue 2” appears before “Issue 1”?

I am using the Astra theme.

Thanks for any help with this,
Carrie