Earlier quoted context omitted.
As mentioned in the post, you need to register for the repository. Steps are below: "If you see a 404 page, you need to complete the enrollment process: Create a GitHub account. Sign up for the Epic program Follow the instructions to associate your Epic Program account with your GitHub account. Join the Epic GitHub Org (from the email invitation you receive after Step 3)"
I hope somebody mirrors this elsewhere. This is just perverse.
It is hard because this is the way for the EULA and Licanse of the software to be enforceable.