Cannot use `packages.${system}.default`: function 'minegrub' called without required argument 'boot-options-count'

[UlyssesZh]

(builtins.getFlake "github:Lxtharia/minegrub-theme").packages.${builtins.currentSystem}.default

error:
       … while evaluating the attribute 'packages.x86_64-linux.default'
         at /nix/store/ypk21myg6psifx2nn58wn446x0bqa4ng-source/flake.nix:115:11:
          114|         (pkgs: {
          115|           default = minegrub {
             |           ^
          116|             inherit pkgs;

       … from call site
         at /nix/store/ypk21myg6psifx2nn58wn446x0bqa4ng-source/flake.nix:115:21:
          114|         (pkgs: {
          115|           default = minegrub {
             |                     ^
          116|             inherit pkgs;

       error: function 'minegrub' called without required argument 'boot-options-count'
       at /nix/store/ypk21myg6psifx2nn58wn446x0bqa4ng-source/flake.nix:21:9:
           20|       minegrub =
           21|         { pkgs, splash ? "", background ? "", customSplash ? splash != "", boot-options-count, ... }:
             |         ^
           22|         pkgs.stdenv.mkDerivation {