Where / How to add a Buy with Prime button Code Snippet

I am included in the invite-only Buy with Prime. They have provided a code snippet but when I paste it as text in the description, it doesn’t render. They suggest I put it in the template. Where would that template be? I am using Pearl theme from WeltPixel if that changes anything.

Here is the snippet, by the way:

<!-- Beginning of Buy With Prime Widget -->
<script defer src='https://bootstrap.prod.scoville.dubai.aws.dev/bwp.js'></script>
<div
    id="amzn-buy-now"
    data-site-id="xxxxxxx"
    data-widget-id="w-yyyyyyyyyyyy"
    data-sku="{{product.sku}}"
></div>
<!-- End of Buy With Prime Widget -->