перейти на сайт с веб-уведомления FireBase

Question

Я создаю сервис, который отправляет веб-push-уведомления, с php и firebase.уведомление работает хорошо, но я не могу добавить ссылку для отправки пользователя на другой сайт.запрос сделан с curl php.this event.data ||event.data.notification всегда null.

self.addEventListener('notificationclick', function (event) {
    let nextUrl = event.notification.data.click_action; // ALWAYS NULL
    console.log('[Service Worker] Notification click Received.', nextUrl);
    event.notification.close();

    event.waitUntil(
        clients.openWindow(nextUrl)
    );
});

здесь весь код .. firebase-messaging-sw.js

// [START initialize_firebase_in_sw]
importScripts('https://www.gstatic.com/firebasejs/5.5.9/firebase-app.js');
importScripts('https://www.gstatic.com/firebasejs/5.5.9/firebase-messaging.js');

// messagingSenderId.
firebase.initializeApp({
    'messagingSenderId': '***'
});

// messages.
const messaging = firebase.messaging();
// [END initialize_firebase_in_sw]

messaging.setBackgroundMessageHandler(function (payload) {
    console.log('[firebase-messaging-sw.js] Received background message ', payload);

    // Customize notification here
    const notificationTitle = payload.data.title;
    const notificationOptions = {
        body: payload.data.body,
        icon: payload.data.icon,
        image: payload.data.image,
        click_action: payload.data.nextLink
    };

    return self.registration.showNotification(notificationTitle,
        notificationOptions);
});
// [END background_handler]

self.addEventListener('notificationclick', function (event) {
    let nextUrl = event.notification.data.click_action; // ALWAYS NULL
    console.log('[Service Worker] Notification click Received.', nextUrl);
    event.notification.close();

    event.waitUntil(
        clients.openWindow(nextUrl)
    );
});

self.addEventListener('install', event => {
    self.skipWaiting();
});

main.js

// Initialize Firebase
var config = {
    apiKey: "***",
    authDomain: "***",
    databaseURL: "***",
    projectId: "***",
    storageBucket: "***",
    messagingSenderId: "***"
};
firebase.initializeApp(config);

// Retrieve Firebase Messaging object.
const messaging = firebase.messaging();

let newUser = {};
let isSubscribed = false; // TODO

if ('serviceWorker' in navigator && 'PushManager' in window) {
    messaging.requestPermission().then(function () {
        return messaging.getToken();
    }).then(function (token) {
        window.localStorage.setItem('token', token); // TODO

        newUser = {
            endPoint: token,
            dateClicked: new Date().toLocaleDateString(),
            hourClicked: new Date().toLocaleTimeString()
        }
        if (!checkIfExist()) {
            $.ajax('***' + token + '.json', {
                accept: "application/json",
                method: 'PUT',
                contentType: "application/json; charset=utf-8",
                dataType: "json",
                data: JSON.stringify(newUser),
                error: function (err) {
                    console.log('Unable to save user in DB.', err);
                }
            });
        } else {
            console.log("User Already Exist");
        }
    })
    .catch(function (err) {
        console.log('Unable to get permission to notify.', err);
    });
}

function checkIfExist(token) {
    return window.localStorage.getItem('token') === token;
}

// ForeGround
// messaging.onMessage(function (payload) {
//     console.log("Message Received");
//     notificationTitle = payload.data.title;
//     notificationOptions = {
//         body: payload.data.body,
//         icon: payload.data.icon
//     };
//     var notification = new Notification(notificationTitle, notificationOptions);
//     console.log(notification);
// });