How can i use additionalData in push notification?

Ionic Framework ionic-v3
1

Hi,
I am a newbie of ionic.
I’m looking for a solution to handle notification but i don’t know how i can to send a custom parameter.
I want to pass Id to notification.
I found from google and it said that i can use “additionalData” and nothing much.
my code:

 "notification": {   
                     "title": "hello",
                    "message": "My test" ,
                        "additionalData":{
                             "id": 1
         }
 }

And in “app.component.ts”:

this.push.rx.notification()
    .subscribe((msg: any) => { 
         var id = msg.additionalData.id;//
           //call alert(...)
      }); 
   });

I suspect it is wrong because i didn’t get any notification when i used this code.
please help.