Few problems in the Hetzner dedicated AX41 zfs-uefi-nvme-nixos.sh script:

[HanEmile]

I've set it up and it's working now, just want to document some problems which came up here for other people:
(This Issue was written on 2023-03-09 (yyyy-mm-dd), might have changed if you're reading this).

• You don't need Ubuntu installed, but the Rescue System
• The Rescue System kernel is to new for installing zfs via get: you can use the "zfs" script provided by Hetzner to build it from source
  • just execute zfs in the rescue shell, if zfs isn't installed yet, it'll try to install it.
• the NIX_PATH has to be set, I set it to the following just above the PATH="$PATH" NIX_PATH="$NIX_PATH" ... line and it just worked:
  • export NIX_PATH=${NIX_PATH:+$NIX_PATH:}$HOME/.nix-defexpr/channels

[ThyMYthOS]

Maybe temporary problem: The zfs in the rescue system is already 2.2.1 while nixos stable is still at 2.1.13. So the created pools cannot be imported if you don't provide -o compatibility=openzfs-2.1-linux