Notice, these things might be missing:
nix --extra-experimental-features "nix-command flakes" build ".#nixosConfigurations.chapel.config.system.build.toplevel"
(replace "chapel" with the hostname)
nixos-rebuild switch --update-input nixpkgs --update-input unstable --no-write-lock-file --refresh --flake github+felixalbrigtsen/nixos-server-conf.git --upgrade