@liaizon I don't think you can, you just clone it using git.

Fork is more like a UI affordance for making a new git repo and then cloing the contents of another repo plus a pointer to upstream. The feature you want would be something like "federated fork" since it would need a flow similar to remote follow on the fediverse to establish the context for the fork and such.

"Clone is VS Code" is pretty friendly though since you don't have to copy paste the repo url or run git manually.