This distribution contains an installer image with a bunch of applications already configured. You should copy it to removable media to perform the bootstrapping phase on physical hardware.
For example:
[you@somewhere:~/site-configs]$ nix build \
--override-input nixpkgs github:nixos/nixpkgs/nixos-22.05 \
--print-build-logs \
'.#installer'
[...]
[you@somewhere:~/site-configs]$ sudo dd \
if=result/iso/nixos-22.05.*-x86_64-linux.iso \
of=/dev/sdb \
status=progress
[...]