It took me a while to figure this out today and hopefully will help someone along the way.
I saw a post about Lemmy Explorer, a website that lets you find new to you magazines across the federated servers. Great! I thought just what I need to find topics that interest me. So I found some magazines I wanted to subscribe to on kbin and first clicked magazines to search for them but none showed up. “Huh” Next I tried the convenient copy function on Lemmy Explorer and pasted the copied text both under magazines in the search bar and into the search on the front page of kbin. Neither worked for me.
The fix is pretty simple. When you copy from Lemmy Explorer the text copies like this example “!linux@lemmy.ml” all you need to do is remove the “!” at the start making it “linux@lemmy.ml” or “technology@beehaw.org”. Paste the text with the “!” removed into the search bar on the front page of kbin and you will see the magazine pop up. From there you can subscribe to that magazine.
This is without a doubt well known to legacy users of kbin but as a new user I was struggling to figure it out.