Help with setting up category moderators on my site

Can you explain what you mean by that? Almost all Discourse versions have ‘beta’ in their name. That doesn’t mean they aren’t reliable; it’s simply the term used to describe milestones in the development of a new version. This means that ‘beta’ versions are usually very up to date, so I would expect that you should be able to use the category moderator feature, which has existed since 2020.