Get a shops permanent url from inside an App Web Pixel

Alright community, hopefully I’m just missing something here. From inside my App Web Pixel, I am registering an event listener :

analytics.subscribe('checkout_completed', (event) => {

Inside that subscribe function, I’m wanting to get the permanent url for the shop that the checkout came from but I can’t find a way anywhere to get access to it from the Shopify API: https://shopify.dev/docs/api/web-pixels-api/standard-api

Any ideas on how I can get it? As always, thanks for your generosity with your time and wisdom.

I’d also like to know how to do this.

Anyone?

There is a document.location available in the context found here:
https://shopify.dev/docs/api/web-pixels-api/standard-api/init#properties-propertydetail-context

I am using init.context.document.location.hostname for finding the originating domain.