Zipping repository contents

We’re wanting to automatically create a zipfile of a repository and email it. I’ve been trying things out on my PC using Git Bash and then using hooks to do the work and this is working as expected but now I’m wanting to do it on our main system which uses GitLab. I’ve so far managed to create a custom hook and use pre-receive which is posting out an email but I’m struggling with the zipfile - I can zip files okay but where are my repository files kept?