scription object on IndexedDB.
    -->
    <amp-web-push-widget visibility="unsubscribed" layout="fixed" width="500" height="70">
        <button on="tap:amp-web-push.subscribe">Subscribe to Notifications</button>
    </amp-web-push-widget>

    <!-- Clicking the unsubscription widget signals the worker to unsubscribe the user from push in the background. On this example, we'll be also removing the previoulsy stored subscription object from IndexedDB.
    -->
    <amp-web-push-widget visibility="subscribed"