Add nixmacs to your flake.nix inputs:

inputs = {
  nixpkgs.url = "github:NixOS/nixpkgs";

  nixmacs = {
    url = "github:yvnth/nixmacs";
    inputs.nixpkgs.follows = "nixpkgs";
  };
};

This config is still under active development, so you may encounter bugs or breaking changes from time to time.

For the complete list of keybindings, see KEYBINDS.org