Pushing (from GoGS) with `post-receive` (to a mirror)

I have a GoGS server for my work. I want to back it up off-site to our GitLab instance. According to a document I read this should be possible using post-receive hooks. Follow me on this magical adventure to git-enlightenment. I’m doing all of this by editing my post-receive hook and then force-pushing a nonsense commit to kick git. Pre-Work Digging around in the GoGS repository settings turned up a panel to edit the hooks.