How do I receive data (key: value) when IOS receives a notification?

[seohangyu]

There is no problem when the app is on.(onMessageReceived) But I do not know how to get it when the app is off.

[lini]

The callback will not be invoked on iOS if you tap the application icon after you receive a notification. The callback should be invoked if you tap the notification itself while the app is open in the background. These behaviors are governed by Apple and you should check the developer documentation or sites like StackOverflow for more information on the subject.