Nix doesn’t even install on my Mac; for reasons I don’t understand.

> Creating a Nix Store volume... error: refusing to create Nix store volume because the boot volume is FileVault encrypted, but encryption-at-rest is not available. Manually create a volume for the store and re-run this script. See https://nixos.org/nix/manual/#sect-macos-installation

The provided link doesn’t really tell me what to do...? Why are there so many (complicated) ways to install this thing, and why can’t it do it automatically?