> If I want to fork your code and contribute back, that means I need to be on the same system as you.

You really don't. You just clone, code, commit, and send a patch (which is just one or more text files). That's it. You may just code and do a diff, if it's a simple fix.

The project may have a more complex policy to accept contributions. But a Fork and a PR is not a requirement.

OK. Let's say I clone to my local machine, make some changes, and commit.

How do I submit the patch to the repo on GitHub / GitLab / CodeBerg / whatever?

Presumably I need to hunt down the maintainer's email?