Adding to this for clarity as I just tried this out: When you use the community search you do in fact need the whole URL --> “https://kbin.social/m/tech”

Additionally you can manually edit the URL by adding the magazine name to “https://lemmy.world/c/” So for “[email protected]” the URL becomes --> “https://lemmy.world/c/[email protected]”

From there you can subscribe. I’ve found that you need to hit the subscribe button twice and it will say “subscribe pending” but it will still show up in your subscribed feed.