mylloon.fr/templates/libs/katex_footer.html

<script
  defer
  src="//cdn.jsdelivr.net/npm/katex@0.16.6/dist/katex.min.js"
  integrity="sha384-j/ZricySXBnNMJy9meJCtyXTKMhIJ42heyr7oAdxTDBy/CYA9hzpMo+YTNV5C+1X"
  crossorigin="anonymous"
></script>
<script
  defer
  src="//cdn.jsdelivr.net/npm/katex@0.16.6/dist/contrib/auto-render.min.js"
  integrity="sha384-+VBxd3r6XgURycqtZ117nYw44OOcIax56Z4dCRWbxyPt0Koah1uHoK0o4+/RRE05"
  crossorigin="anonymous"
></script>
<script>
  window.addEventListener("load", () => {
    const macros = {};
    for (const item of new Map(
      Object.entries({
        N: "mathbb{N}",
        R: "mathbb{R}",
        Z: "mathbb{Z}",
        O: "Theta",
        ra: "rightarrow",
        la: "leftarrow",
        RA: "Rightarrow",
        LA: "Leftarrow",
      })
    )[Symbol.iterator]()) {
      macros[`\\${item[0]}`] = `\\${item[1]}`;
    }

    renderMathInElement(document.body, {
      delimiters: [
        { left: "$$", right: "$$", display: true },
        { left: "$", right: "$", display: false },
      ],
      throwOnError: false,
      macros,
    });
  });
</script>