It says the discord link has expired. Is it already too late to join? 

Suspect it is a mistake, link is a typo, or expired and it should not have.
Think this is the correct link? https://discord.gg/hs37bev
found at: https://forums.unrealengine.com/community/community-content-tools-and-tutorials/...

It's defintely not too late to join, it was just a link error. You can find the fixed link on the main page or above.

Best of luck,

Luke Anderton / Virtus Learning Hub