I honestly can’t imagine why there would be tags if you can’t search by them and the FAQs are a maze of uselessness for such a simple question.
I’m using the Community version on my own server, installed from Softaculous. Is it simply not a feature or is there a setting, upgrade, or add-on required?
I think no. Most of the functionality was made for logged in ownCloud users, not for the public. Otherwise, put a feature request on GitHub, but I doubt you’ll have any success. I’m sorry.