Unable to process data from push notification in IOS - flutter

Question

I have set up everything and i do receive a push notification but I am unable to process it. i.e I want a pop up window to show together when i receive the message. The pop
As the notification is received i want to use this function retrieveRideRequestInfo(getRideRequestId(message.data)!, context); to get the data in the notification and build a pop up window. On IOS i get Null check operator used on a null value at (message.data)!
This is the getRideRequestId function
String? getRideRequestId(Map<String, dynamic> message) {
String? rideRequestId = "";
if (Platform.isAndroid) {
// print();
rideRequestId = message['ride_request_id'];
print("This is ride request ID :$rideRequestId");
} else {
//for ios
rideRequestId = message['data'];
}
//doublenotification++;
return rideRequestId;
}
In android it works fine but in Ios I get an error Null check operator used on a null value This is at retrieveRideRequestInfo(getRideRequestId(message.data)!, context);
This is How i send the notification from another device, Is it correct ror ios ?
static sendNotificationToDriver(
String token, context, String rideRequestId) async {
try {
await http.post(
Uri.parse('https://fcm.googleapis.com/fcm/send'),
headers: <String, String>{
'Authorization': serverToken,
'Content-Type': 'application/json',
},
body: jsonEncode({
"to": token,
"collapse_key": "type_a",
"notification": {
"body": "Nepali Rider",
"title": "You have a new Ride"
},
"data": {"ride_request_id": rideRequestId}
}),
);
print('FCM request for device sent!');
} catch (e) {
print(e);
}
print("ride request id :$rideRequestId");
print("ride request id :$token");
print(jsonEncode);
}