Push notifications

support.js

// Check if the browser supports push notifications.
if ("serviceWorker" in navigator && "PushManager" in window) {
  try {
    // Register the service worker.
    const swReg = await navigator.serviceWorker.register("/sw.js");

    // Subscribe for push notifications.
    const pushSubscription = await swReg.pushManager.subscribe({
      userVisibleOnly: true
    });

    // Save the push subscription to the database.
    savePushSubscription(pushSubscription);
  } catch (error) {
    // Handle errors.
    console.error("Error subscribing for push notifications.", error);
  }
} else {
  // Push notifications are not supported by the browser.
  console.error("Push notifications are not supported by the browser.");
}

via: https://web.dev/push-notifications-in-all-modern-browsers/