How to show MathJax equations in web version?

Anki Desktop
1

Hello. I use symbols mathjax like this: \(a=x+2\pi k\)
In the desktop version it’s OK, but in the web version my formulas don’t show.
I’ve tried to put next code to before question:

<script type="text/x-mathjax-config">
MathJax.Hub.processSectionDelay = 0;
MathJax.Hub.Config({
  messageStyle: 'none',
  showProcessingMessages: false,
  tex2jax: {
    inlineMath: [['\(', '\)']],
    displayMath: [['\(', '\)']],
    processEscapes: true
  }
});
and I've put the next code after qiesion: 
<script type="text/javascript">
(function() {
  if (window.MathJax != null) {
    var card = document.querySelector('.card');
    MathJax.Hub.Queue(['Typeset', MathJax.Hub, card]);
    return;
  }
  var script = document.createElement('script');
  script.type = 'text/javascript';
  script.src = 'https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.1/MathJax.js?config=TeX-MML-AM_CHTML';
  document.body.appendChild(script);
})();
</script>

but it didn’t work.

Here’s a solution:

<script type="text/x-mathjax-config">
MathJax.Hub.processSectionDelay = 0;
MathJax.Hub.Config({
  messageStyle: 'none',
  showProcessingMessages: false,
  tex2jax: {
    inlineMath: [ ['$','$'], ['\\(','\\)'] ],
    displayMath: [ ['$$','$$'], ['\\[','\\]'] ],
    processEscapes: true
  }
});
</script>
3

There’s no MathJax in the web version right now.