Voximplant push notifications demo page

Add a [web app manifest](https://developers.google.com/web/fundamentals/engage-and-retain/web-app-manifest/) that specifies the `gcm_sender_id`, a hard-coded value indicating that FCM is authorized to send messages to this app. If your app already has a `manifest.json` configuration file, make sure to add the browser sender ID exactly as it is shown below (do not change the value): ```json { "gcm_sender_id": "103953800507" } ``` Create an `index.html` file for this demo app. Copy and paste this markup into it: ```html Voximplant push notifications demo page ``` Add the core Firebase and Firebase Messaging SDKs to your project by adding the `script` tag to the bottom of the `body` tag in your `index.html`: ```html ``` In a real-world app, you may also add them by using a packet manager: ```console yarn add @firebase/app yarn add @firebase/messaging ``` Add the Voximplant Web SDK after the Firebase scripts: ```html ``` Add a `main.js` file to your push notifications demo app and link it to your `index.html file`: ```html ``` Switch to the [General](https://console.firebase.google.com/u/0/project/_/settings/general/) tab in **Settings** of the Firebase console, scroll to **Your apps**, and add a new web app – Firebase will provide you with your web app's Firebase configuration. Copy and paste a `firebaseConfig` variable into the `main.js` file before you use any Firebase services: ```javascript const firebaseConfig = { apiKey: "AAAAaaaaaaaaaaaaaaaaaaaaaaaaaa", authDomain: "voximplant-11111.firebaseapp.com", databaseURL: "https://voximplant-11111.firebaseio.com", projectId: "voximplant-11111", storageBucket: "voximplant-11111.appspot.com", messagingSenderId: "1111111111111", appId: "1:1111111111111:web:111111111111111" }; ``` Initialize Firebase: ```javascript firebase.initializeApp(firebaseConfig); ```