How to send a POST request to Firebase Cloud Messaging API in Vapor

1. In sendNotification(payload:) I had a typo, I missed = after key. It should have been "key=\(fcmLegacyServerKey)"
2. In sendNotification(payload:), payLoad.makeBody should not be called, I should have just passed the JSON object payLoad as an argument to the .post request.
3. The JSON object of the notification was clearly badly formatted from the outset. The message type I wanted to send was notification, but I was passing in a key named aps. I should have passed key notification as shown below.

.

class FirebaseRequester {

  let fcmLegacyServerKey = "AIzaSy....vVos"

  func sendNotification(payLoad: JSON) throws -> Response {

  var response: Response?
   do {
     let responseFCM = try drop.client.post("https://fcm.googleapis.com/fcm/send", 
       headers: ["Content-Type":"application/json","Authorization": "key=\(fcmLegacyServerKey)"], 
       query: [:], 
      body: payLoad

      response = responseFCM

  }catch let error {
     let message = error.localizedDescription
     logErr.prints(message: message)
     throw Abort.custom(status: .badRequest, message: message)
 }
   guard let rsp = response?.json else {

    let message = "no json received on line \(#line)"
    drop.log.error(message)
    logErr.prints(message: message)
    throw Abort.custom(status: .badRequest, message: message)
   }
    return response!
  }//end of sendNotification()
}//end of class FirebaseRequester



class TestRouteNow {

  let firebaseRequester: FirebaseRequester

  init(firebaseRequester: FirebaseRequester) {
     self.firebaseRequester = firebaseRequester
  }

  func addRoutes(drop: Droplet) {
     drop.post("test", "notif", handler: postNotification)
  }

   func postNotification(request: Request) throws -> ResponseRepresentable {

   let fcmDevice = "someDeviceTokenReceivedFromClientApp"
   let data = try Node(node: ["title": "title","body": "body", "sound": "default", "badge":"60"])

    var payLoadObj = try JSON(node: ["notification": data])
    payLoadObj["to"] = try JSON(node: fcmDevice)

      do {
        let _ = try firebaseRequester.sendNotification(payLoad: payLoadObj)
            }catch{
                logErr.prints(message: error.localizedDescription)
            }

            let message = "notification Sent"
            return try JSON(node:["success":message]) 
     } 
 }//end of class




    // request body
{
  "to" : "cQDtm_someDeviceTokenReceivedFromClient",
  "priority":"high",

 "notification": {
     "title":"Booking Rescheduled",
      "body": "Cancelled Booking 7830593, for Mon, 12 March",
      "sound":"default",
     "badge": "100"
  }
}