Script async src widget not displaying

I cannot seem to get the below to work on a post. Are Scripts not permitted? Do i need anything else to make this work?

The quote and link works, but the script widget doesn’t.

<blockquote class="embedly-card"><h4><a href="">Daniel Green</a></h4><p>Lighting designer, budding writer, and graphical tinkerer...</p></blockquote>
<script async src="//" charset="UTF-8"></script>

JS isn’t allowed inside posts right now, no. Maybe you could embed it at the blog level, as mentioned here? Extended JS Support

If I manage to embed it at blog level, how do I display it on a particular page?

Ignore the above, I got it to work! Thanks once again.

Example of working Custom JS with Emebly for a Dribbble card.