I send from Firebase Messages in this structure:
{
    "to": "/topics/myapp",
    "data": {
        "id" : "id123",
        "title" : "lksdjkrfrfrereflsjd",
        "body" : "fsdfsd",
        "de": {
            "key1" : "val1",
            "key2" : "val2"
         },
        "en": {
            "key3" : "val3",
            "key4" : "val4"
         }
     }
}
in my override fun onMessageReceived(remoteMessage: RemoteMessage?) method my remoteMessage object has a data field which is from type: Map<String, String> 
How can I access de and en from remoteMessage ?
EDIT: It is developed for Android
