Cloudkit Server-To-Server auto-renew subscription

I see in the documentation to receive updates if a customer cancels their auto-renewing subscriptions, you must provide a url to Apple on the AppStore connect site. What i don't understand is what if I don't have my own server? rather I'm just using Cloudkit to host all my data? Am I missing something very obvious on where to receive notifications for these subscriptions through Cloudkit?