Page Code/Setup:

<script src="https://fast.wistia.com/assets/external/E-v1.js" async></script>

The E-v1.js script is loaded directly into the page header on this page. I broke it out from the embed "Code Element" below.

<script src="https://fast.wistia.com/embed/medias/mw3obnexwb.jsonp" async></script>
<div class="wistia_embed wistia_async_mw3obnexwb" style="width:100%;">&nbsp;</div>

The above is pasted directly into a Webflow "Code Embed" element.