It’s bugging out right now, probably because of the massive amount of traffic, but once things calm down you should be able to search for a magazine by full URL (https://kbin.social/m/gaming, for example) in communities, switch all search settings to all, wait for your instance to pull in the magazine and click through to the federated URL (should look like https://lemmy.world/c/gaming@kbin.social, assuming you’re on lemmy.world)
Basically, just like adding a community nobody else on your instance has added before.
How does one do that?
It’s bugging out right now, probably because of the massive amount of traffic, but once things calm down you should be able to search for a magazine by full URL (https://kbin.social/m/gaming, for example) in communities, switch all search settings to all, wait for your instance to pull in the magazine and click through to the federated URL (should look like https://lemmy.world/c/gaming@kbin.social, assuming you’re on lemmy.world)
Basically, just like adding a community nobody else on your instance has added before.