javascript - Firebase success notification doesn't appear in browser -

i'm trying implement browser push notifications using fcm. project based on angular 2.

in app.module.ts i've registered firebase application.

import { angularfiremodule, firebaseappconfig } "angularfire2";  const firebaseconfig = {   apikey: "test",   authdomain: "test",   databaseurl: "test",   storagebucket: "",   messagingsenderid: "328947432649" };  imports: [     angularfiremodule.initializeapp(firebaseconfig)   ], 

i've created firebase-messaging-sw.js

importscripts('https://www.gstatic.com/firebasejs/3.7.2/firebase-app.js'); importscripts('https://www.gstatic.com/firebasejs/3.7.2/firebase-messaging.js');    firebase.initializeapp({   'messagingsenderid': 'test' });  firebase.messaging();  self.addeventlistener('notificationclick', function (event) {   const target = event.notification.data.click_action || '/';   event.notification.close();    // looks see if current open , focuses if   event.waituntil(clients.matchall({     type: 'window',     includeuncontrolled: true   }).then(function (clientlist) {     // clientlist empty?!     (var = 0; < clientlist.length; i++) {       var client = clientlist[i];       if (client.url == target && 'focus' in client) {         return client.focus();       }     }      return clients.openwindow(target);   })); }); 

i've created messagingservice

import { injectable, inject } '@angular/core'; import { http, response, headers, requestoptions } "@angular/http"; import 'rxjs/add/operator/map'; import 'rxjs/add/operator/catch'; import { firebaseapp } "angularfire2"; import * firebase 'firebase'; import { httpservice } "app/services/http.service"; import { observable } "rxjs/rx";  @injectable() export class messagingservice {      private currenttoken: string = "";     private _messaging: firebase.messaging.messaging;      constructor(private httpservice: httpservice, @inject(firebaseapp) private _firebaseapp: firebase.app.app) {          this.currenttoken = json.parse(localstorage.getitem('firebase_token'));         this._messaging = firebase.messaging(this._firebaseapp);     }      getnewtoken() {          this.requestpermission();     }      private requestpermission() {         this._messaging.requestpermission()             .then(() => {                 this.gettoken();             })             .catch(err => {                 console.log('unable permission notify.', err);             });     }      private gettoken() {         this._messaging.gettoken().then(token => {             if (this.currenttoken === token) {                 this._messaging.deletetoken(token).then(() => {                     this.deletetokenfromserver(token);                     this._messaging.gettoken().then(                         refreshedtoken => {                             this.currenttoken = refreshedtoken;                             this.savetoken(this.currenttoken);                          }                     ).catch(err => {                         console.error('msg token error:', err);                     });                 });             }             else {                 this.currenttoken = token;                 this.savetoken(this.currenttoken);              }         });     }      private savetoken(token: string) {         this.currenttoken = token;         localstorage.setitem('firebase_token', json.stringify(this.currenttoken));         this.sendtokentoserver(token);     }      private sendtokentoserver(token: string) {         const body = {             browsertoken: token         }         this.httpservice.post(`/pushbrowsernotification/addbrowsertoken`, body).subscribe()     }      private deletetokenfromserver(token: string) {         const body = {             browsertoken: token         }         this.httpservice.post(`/pushbrowsernotification/removebrowsertoken`, body).subscribe();     } } 

when i'm logging site, i'm calling getnewtoken() method in component. after allow notification on site. i've gotten fire-base token , working service worker.

after i'm trying send notification using postman. @ first works well. i'm getting notifications. after waiting of order of 10 seconds, click send button , nothing happens. these notifications don't work anymore. when change icon, starts work again time. what's wrong implementation?