GitHub has added support for securing SSH Git operations using FIDO2 security keys for added protection from account takeover attempts.

When you add a security key to SSH operations, you can use these devices to protect you and your account from accidental exposure, account hijacking, or malware, GitHub security engineer Kevin ...

If one has an SSH key registered with the account, one can use SSH authentication to recover the account in cases where all of the other authentication methods have become unavailable.

-Protocols For URLs with a "git://" scheme a different network transport (by default using tcp port 9418) is used. URLs with no scheme use ssh.