I’ve tried registering but every time I do, it says to click the link in the email they send me. The problem is, I don’t get the email 🤔 any suggestions on how to fix this?

Check your junk and all that, but also try a different email. Old stuff sometimes scuffed

The Discord server of the MKDS community offers a service which can send your submissions Discord too, in case you can't solve the issue. But yeah, good luck solving it out as the site is very old and has its problems due to that.