Mirror gitlab-ce Repository using ssh key

Is it possible to use ssh to push mirror a repo between gitlab-ce and gitlab-ce ?

We are currently running a local version of gitlab-ce 14.5.2 and wish to find a good way to create a backup/mirror repository.

We setup a new gitlab-ce repo with the same version as a backup repo but when we try to use ssh to push the repo to this server it fails with a permission error. I have the same user on both repo’s with maintainer role and copied over the ssh key details.

Just wondering if anyone else has this working ?

There is a lot to read about it here : Repository mirroring | GitLab

I was not able to make it work.