How to install on self-hosted GitLab

Hi,

Reading README, it's not clear how to install this theme on a self-hosted GitLab instance with a custom URL which does not have "gitlab" in it. I do have it installed in Stylus extension, but it's not showing up on the list of themes when I am on our GitLab site. How do I assign this theme to a custom URL? Thank you very much.

Browser: Chrome

Dark-GitLab version: v0.56

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information