How we implemented Apple Server To Server notifications

I use Auto-Renewable Subscription in my application. When I test it I want to cancel Auto-Renewable Subscription in Sandbox environment and i want to implement Apple notification (Server to Server (S2S) notifications) to understand when a user purchases, renews, cancels their premium subscription, but I haven't received anything back.

Can you give me an example of how to develop an endpoint that would consume the notification with Laravel to get the cancellation date?

Once this is fixed will notifications start sending to our servers when I test in sandBox.

Thank you!

via Chebli Mohamed