<!DOCTYPE html>
<html>

    <head>
        <title>React Dropdown Tree Select Demo</title>
        <link href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" integrity="sha384-wvfXpqpZZVQGK6TAh5PVlGOfQNHSoD2xbE+QkPxCAFlNEevoEH3Sl0sibVcOQVnN"
            crossorigin="anonymous">
    </head>

    <body>
        <div id="app"></div>
        <script src="bundle.js"></script>
    </body>

</html>
<!DOCTYPE html>
<html>
  <head>
    <title>React Dropdown Tree Select Demo</title>
    <link
      href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css"
      rel="stylesheet"
      integrity="sha384-wvfXpqpZZVQGK6TAh5PVlGOfQNHSoD2xbE+QkPxCAFlNEevoEH3Sl0sibVcOQVnN"
      crossorigin="anonymous"
    />
  </head>

  <body>
    <div id="app"></div>
    <script
      crossorigin="anonymous"
      src="https://polyfill.io/v3/polyfill.min.js?features=Array.prototype.find%2CPromise"
    ></script>
    <script src="bundle.js"></script>
  </body>
</html>

Bring in polyfills for IE11 📚
docs: Bring in polyfills for IE11 📚
