Accessing flake from self-hosted git repo

I have a git repo with my flake configuration self-hosted on my server and available via https that I can successfully git clone https://<url>/nixos.

However, I’m unable to access that flake via nix:

$ sudo nixos-rebuild --flake git+https://<url>/nixos#laptop build 
error: getting status of '/nix/store/xgjny8m0ag7gh58db387b2hmmzncm19j-source/flake.nix': No such file or directory.

Any ideas? Thanks!