Passing data from firebase-service-worker to Flutter web app

Question

I've successfully been able to establish FCM in my Flutter web app and FirebaseMessaging.onMessage is working fine, but when receiving a message while my app is in the background I have this in the FirebaseFlutter docs: Right now, all web background code must be executed in the JavaScript Service Worker file. So I want to pass Firebase notification data m.data.type and m.data.id to my Flutter app to be able to handle the events. I can't load my firebase-service-worker in a script Firebase messaging importScripts is not defined I can't use window because my code doesn't run in the browser. (self is not passing the data).

importScripts("https://www.gstatic.com/firebasejs/8.6.1/firebase-app.js");
importScripts("https://www.gstatic.com/firebasejs/8.6.1/firebase-messaging.js");

firebase.initializeApp({
  apiKey: "key",
  authDomain: "authDomain",
  projectId: "id",
  storageBucket: "",
  messagingSenderId: "",
  appId: "1::",
  measurementId: "G-",
});
var notificationClick = false;
clients
  .matchAll({ type: "window", includeUncontrolled: true })
  .then(function (clientList) {
    console.log(clientList);

    for (var client of clientList) {
      client.postMessage({
        msg: "Hey I just got a fetch from you!",
      });
      client.state = {
        type: "type",
        id: "id",
      };
    }
  });

const messaging = firebase.messaging();

messaging.onBackgroundMessage((m) => {
  console.log(notificationClick);
  var type = m.data.type;
  var id = m.data.id;
  if (m.data.type == "NewOrder") {
    console.log(m.data.type);
    console.log(m.data.id);
  }
  if (m.data.type == "UpdateOrder") {
    console.log(m.data.type);
    console.log(m.data.id);
  }
  if (m.data.type == "NewOrderTab") {
    console.log(m.data.type);
    console.log(m.data.id);
  }
  if (m.data.type == "UpdateOrderTab") {
    console.log(m.data.type);
    console.log(m.data.id);
  }
  if (m.data.type == "NewTable") {
    console.log(m.data.type);
    console.log(m.data.id);
  }
  if (m.data.type == "UpdateTable") {
    console.log(m.data.type);
    console.log(m.data.id);
  }
  const notificationTitle = m.data.title;
  const notificationOptions = {
    body: m.data.type,
    type: m.data.type,
    id: m.data.id,
  };
  console.log(notificationOptions);
  self.state = {
    type: type,
    id: id,
  };

  // window.state = {
  //   type: type,
  //   id: id,
  // };
  clients
    .matchAll({ type: "window", includeUncontrolled: true })
    .then(function (clientList) {
      console.log(clientList);

      // No match by default
      var matchFound = false;

      // Traverse clients list
      for (var client of clientList) {
        client.postMessage({
          msg: "Hey I just got a fetch from you!",
        });
        client.state = {
          type: type,
          id: id,
        };
      }
    });

  return self.registration.showNotification(
    notificationTitle,
    notificationOptions
  );
});

self.addEventListener("notificationclick", function (event) {
  notificationClick = true;
  event.waitUntil(console.log(notificationClick));
});