nix-configs/modules/desktop-environment/home/niri/input.nix

{...}: {
  programs.niri.settings.input = {
    keyboard = {
      xkb = {
        layout = "us";
        variant = "altgr-intl";
      };
    };
    touchpad = {
      tap = true;
      natural-scroll = true;
    };
  };
}