services.github-runners.<name>.url

Repository to add the runner to.

Changing this option triggers a new runner registration.

IMPORTANT: If your token is org-wide (not per repository), you need to provide a github org link, not a single repository, so do it like this https://github.com/nixos, not like this https://github.com/nixos/nixpkgs. Otherwise, you are going to get a 404 NotFound from POST https://api.github.com/actions/runner-registration in the configure script.