Thanks for asking question! We are simply a pass-through to Firebase directly. If you can send that body through Firebase, then you should be able to send it through us. We are using the Legacy FCM endpoint, so anything valid here is sent along Firebase Cloud Messaging HTTP protocol (google.com)
A message can be either a notification message or data message as we have on our portal for test-send.
{
"notification":{
"title":"Notification Hub Test Notification",
"body":"This is a sample notification delivered by Azure Notification Hubs."
},
"data":{
"property1":"value1",
"property2":42
}
}
Nothing more than that should be required.
Let us know if further query or issue remains.