From the front page I expected maybe some web interface for doing various tasks, such as Nix package management or setting up Let's Encrypt, etc, but judging from the docs, everything should be done via standard Nix/NixOS commands in command line. So, I'm sorry, what service Shipnix actually provides, apart from initial setup of the server with NixOS and SSH keys, that would justify paying monthly? At least it's not clear from the docs.