1. If you're playing the game on PC through itch.io (either downloaded from this page or through the itch.io launcher) this version of the game is no longer supported. If you're able to use Steam (some of us can't), the download page here has a Steam key you can redeem.
2. If you're already playing a version other than the itch.io PC version (Epic, Steam or any mobile version), then you can create an account. This needs a date of birth, and I've heard some people say you need to be over 18 for free chat to work.