JSFiddle - React, Tailwind, and code Playground

HTML

<body>
    <!-- This works -->
    <!-- <script type="text/javascript" src="http://www.zoom.it/aaa.js"/> -->
</body>

JavaScript

$(function() {
    // Doesn't seem to work - get "Cannot set property 'innerHTML' of null"
    function loadjscssfile(filename, filetype){
     if (filetype=="js"){ //if filename is a external JavaScript file
      var fileref=document.createElement('script')
      fileref.setAttribute("type","text/javascript")
      fileref.setAttribute("src", filename)
     }
     else if (filetype=="css"){ //if filename is an external CSS file
      var fileref=document.createElement("link")
      fileref.setAttribute("rel", "stylesheet")
      fileref.setAttribute("type", "text/css")
      fileref.setAttribute("href", filename)
     }
     if (typeof fileref!="undefined")
      document.getElementsByTagName("head")[0].appendChild(fileref)
    }
    
    loadjscssfile("http://www.zoom.it/aaa.js", "js")
});