Is it possible to use own SSH-Keys at the repository mirroring?

Hello there!

If you want to mirror a repository, i.e. that the changes are always pulled into the GitLab repository from another Git server, it is possible to specify authentication via an SSH key. A new SSH key is now created for each mirror. Is it possible to specify your own key there? I have many repositories and don’t always want to add an SSH key for each one on the other Git server.

Thanks
Lukas