How to access frontmatter in a markdown-it plugin?

[Octobug]

This closed issue #1122 seems like what I need. But I cannot figure out how to realize it since VitePress has changed a lot from then on.

[brc-dd]

You can access it from env parameter in your renderer.

[Octobug]

Thank you! It took me some time to finally figure it out :D

[Octobug]

e.g.

md.renderer.rules.footnote_block_open = (_tks, _idx, _opts, env) => {
  const { frontmatter } = env;
  const title = frontmatter.footnote || "References";
  ...
};