MathJax.startup.promise timing issue

Created by: holgerengels

Hi .. I have a problem loading mathjax in a webapp.

I am using the following code to load mathjax in my index.html:

  <script>
      function loadScript(url) {
        return new Promise(function(resolve, reject) {
          const script = document.createElement('script');
          script.type = "text/javascript";
          script.async = true;
          script.src = url;

          script.onload = resolve;
          script.onerror = reject;
          document.head.appendChild(script);
        })
      }

      window.MathJax = { loader: {load: ['input/asciimath', 'output/svg']} };

      window.MathJaxLoader = loadScript("https://cdn.jsdelivr.net/npm/mathjax@3/es5/startup.js")
        .then(() => console.log("loaded"))
        .then(() => window.MathJax.startup.promise)
        .then(() => console.log("initialized"))
        .then(() => console.log(window.MathJax.asciimath2svg))
      ;
  </script>

In chrome's console, I see the output ..

loaded
initialized
undefined

Shouldn't window.MathJax.asciimath2svg be defined when the startup.promise has resolved?