Can't join a LAN server.

So I was trying to join my friend on a LAN server, but it just kept saying that I need to use the release candidate, which I am using. I then restarted Minecraft to see if it would give me a different option, which it did, but it was the release of 1.16.5, and I wanted to use the snapshot, because they were using that. I then tried restarting my computer but that did not work either.