Handling Instant Payment Notifications

To receive Instant Payment Notifications with the btcpay-ipn node, set the url path the IPN listener will listen to notifications on.

When BTCPay Server sends a notification to the IPN listener url, it will trigger the node output with the invoice object set to msg.payload. Note: as the incoming data cannot be trusted, the node fetches the actual invoice data via API before triggering the output.