We created accounts on the website to play LFS with my friends, then we tried to log in to the game, but it says "your unlock code does not match." We copied and pasted the passwords and everything, but it still doesn't work.

Did you get the unlock code via email? Is that what you copied and pasted?

The password for the GAME changed to a auto-generate,email delivered, unlock code
https://www.lfs.net/forum/thread/111994-Removal-of-WEB-password-and-GAME-password