iOS critical alert through FCM

Question

iOS 12 has added critical alerts. The APNS payload has the sound dictionary to support critical alerts. Is there an equivalent sound dictionary support in FCM payload to sen

Answer 1

There is currently no sound dictionary support in FCM which is equivalent to iOS' sound dictionary. As I'm sure you're already aware of, the counterpart of FCM with APNs' when it comes to sound is the sound parameter:

The sound to play when the device receives the notification.

Sound files can be in the main bundle of the client app or in the Library/Sounds folder of the app's data container. See the iOS Developer Library for more information.

However, reading from the UNNotificationSound docs, maybe you could try adding a data message payload that contains an identifier (e.g. "isCritical": "true") then have your app handle it as needed.