Javascript onclick not navigating between pages

I have one html file index.html and two html templates that presentation.html and lookup.html.

I have my onClicks setup as such in index.html:

<div class="sidenav">
      <h4 class="sidenav-header"> Header </h4>
      <hr class="style1">

      <button id="presentation-button" onclick="showPresentationScreen()">Presentation Creator</button>
      <hr class="style1">

      <button id="lookup-button" onclick="showLookupScreen()">Lookup</button>
      <hr class="style1">

      <button id="manage-button" onclick="showManageScreen()">Manage</button>
    </div>
   <!-- Sidebar is here-->

   <div id="container"> </div>

   <script>
      require('./assets/intro.js');

      function showLookupScreen() {
         require('./assets/lookup.js');
      }

      function showPresentationScreen() {
         require('./assets/presentation.js');
      }


   </script>

Here is presentation.js and lookup.js:

var link = document.querySelector('#presentation-file');
var template = link.import.querySelector('template');
var clone = document.importNode(template.content, true);

var elem = document.querySelector('#container');
while (elem.firstChild) {
   elem.removeChild(elem.firstChild);
}

elem.appendChild(clone);

var link = document.querySelector('#lookup-file');
var template = link.import.querySelector('template');
var clone = document.importNode(template.content, true);

var elem = document.querySelector('#container');
while (elem.firstChild) {
   elem.removeChild(elem.firstChild);
}

elem.appendChild(clone);

When I run my Electron app, the onClick() works as expected the first time (going from presentation.html -->lookup.html. But when I try going back to presentation.html, it doesn't render the page. Why isn't this working?