Your widget.
On their website.

A small snippet. One shared platform.

The loader auto-sizes the iframe. It checks message origins, sources and a per-instance channel before accepting height updates. The Zoo widget has its own optional donation choice, but runs the same device and quote flow.

<div id="buyaphone-zoo"></div>
<script src="https://sell.buyaphone.ie/widget.js"
  data-container="buyaphone-zoo"
  data-partner="dublin-zoo" defer></script>

Production instructions: configure the approved Zoo domains in the deployment’s frame policy, and test the snippet on a Zoo staging page before replacing Reusely.