Device Registration
Once a user has opt'ed in to recieve push notifications, you can receive a device token via the Firebase sdk. Once you have the device token, you can submit it, along with the customerId (ENID) to the devices endpoint.
This will return an Id for the token added
If a user disables push notifications on the device, then you would need to delete the token so that system doesn't attempt to send a notification to the user.
Other calls are available to look up a customer's tokens:
if you know the device token id, you can use: