Set Default Value to a Slug - How to Set a Standard Value to a Slug

const slugify = require("slugify");

const title = "Test", 
slug = slugify(title, {
  lower: true,
});

export default {
  type: "document",
  title: "Pages",
  name: "page",
  initialValue: {
    title,
    slug: { _type: "slug", current: slug },
  },
  fields: [
    {
      title: "Title",
      name: "title",
      type: "string",
      validation: (Rule) => Rule.required(),
    },
    {
      name: "slug",
      title: "Slug",
      type: "slug",
      options: {
        source: "title",
        slugify: (input) =>
          input.toLowerCase().replace(/\s+/g, "-").slice(0, 200),
      },
    },
  ],
};