Nix
First of all, it is a good idea to set up Cachix before continuing with installing Hyprland.
After getting Cachix working, you have a few options ahead:
Hyprland is NOT supported on NixOS stable. It may (not) compile or work as intended. Please use the flake.
If you’re on NixOS and also use HM, it is a good idea to use Hyprland modules for both. Make sure the package options are the same for both modules.
Read Hyprland on NixOS and Hyprland on Home Manager.
If you do not plan on using the NixOS module, but want to use the HM module, you will have to enable all the options the NixOS module enables.
Read Hyprland on Home Manager.
If you don’t plan on using any module, manually enable all the options that the modules have set.
Read the sources.