Sorry about that, I was not clear at my question. My concern is about the installation. For example, following the official installation instructions gives me this error:
➜ ~ sh <(curl -L https://nixos.org/nix/install) --daemon
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0
100 2490 100 2490 0 0 6029 0 --:--:-- --:--:-- --:--:-- 6029
fish: Invalid redirection target:
sh <(curl -L https://nixos.org/nix/install) --daemon
^