API Detecting Changes Automatically

Does anyone know how to get Bubble’s API to detect when changes are made on an endpoint? For example, in Shopify, I create a new product. I would like Bubble to be able to detect when a new product (or new order for that matter) is created, and write a new entry into the database.

I’ve set up an endpoint and created a webhook in a Shopify store, successfully connecting the two. But how does the API know when I make changes in my store?