The logical thing would be a subscribe button on the community page. That's not there. So I did some digging and apparently you're supposed to paste the community name into search.
I tried that. Initially it just brought up a list of posts that mention that community. I then tried to choose "communities" as a filter and it brought up nothing.
Would someone please tell me what I'm missing? Why is this so hard?
EDIT: Nevermind. It's in the sidebar which I missed because I'm on mobile. 🤦‍♂️
I had the same issue. i'm on Jerboa (android app). It's not very intuitive. I ended up logging in via laptop web browser,and subscribing from there. If anybody has a clue how to subscribe to other communities via Jeboa, it'd be greatly appreciated.