Receiving Event notifications
After registering to get notifications for one or more event types, you need only listen for the associated notifications. When a relevant event is triggered, Conga Sign sends an HTTP POST to your registered URL. That message contains a payload in JSON format, describing the event that triggered the notification. The callback key you registered is passed through the Authorization header as "Basic {callbackKey}". You have use this to make sure you are receiving notifications that contain the shared secret, so you know you are not getting spoof calls and can react accordingly.