saveAs is not defined when using JSzip

There is a comment in their example:

// see FileSaver.js

You need that module if you want to use saveAs()

Here it is: https://github.com/eligrey/FileSaver.js

It works after adding the following script tag in the HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/FileSaver.js/1.3.8/FileSaver.js"></script>