Using pdf.js in a html element

I am using an HTML element in my application. Using the free pdf.js express. This is the code ive been playing with but all that shows up is the pdf express webpage and no viewer. there is also a 404 error. is there something simple im missing or is it related to DNS?

<div id="pdfViewerContainer">
  <iframe id="pdfViewerFrame" src="” style="width: 100%; height: 600px; border: none;"></iframe>

<script src=""></script>
  var pdfUrl = "";
  var viewerContainer = document.getElementById("pdfViewerContainer");
  var viewerFrame = document.getElementById("pdfViewerFrame");

  viewerFrame.onload = function() {
    var pdfViewer = viewerFrame.contentWindow.PDFViewerApplication;

Hi there,

Thank you for reaching pdf.js express forums,

PDF.js express does not have a CDN:

Is there a path to your lib folder containing the static assets somewhere? Is it being properly referenced in your application?

Could you please share a screenshot of console error messages and any failed network requests?

Best regards,
Kevin Kim