index.js

import { serialize } from "next-mdx-remote/serialize";
import { MDXRemote } from "next-mdx-remote";

export default function Home({ source }) {
  return (
    <div>
      <MDXRemote {...source} />
    </div>
  );
}

export const getStaticProps = async () => {
  const source = "```html\n<h1>Hello World</h1>\n```";

  const mdxSource = await serialize(source);

  return { props: { source: mdxSource } };
};