Fix Ckeditor missing style css and error MathJax is not defined

[chuvanhoang888]

I did npm run build and tested sample/index.html but my ckeditor form is missing css style and console shows ReferenceError: MathJax is not defined. Please help me fix it, thank you.

[chuvanhoang888]

2. Problem Error MathJax is not defined - I can manually add script tags to the head but I don't know if this is the right way.
   <script type="text/javascript" id="MathJax-script" src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js">