Register a label number to receive automatic updates when new scan events are processed
Notification options are;
labelno - Label number to receive updates for
pushmethod - The method on which updates are sent. Available options are
{ 'result': { 'inserted': false, 'exists': true }, 'generated_in': '45ms'}
https://nz.api.fastway.org/v7/tracktrace/pushnotification_register/3a0000253492/url/all?api_key=YOUR_API_KEY