By now, we've integrated our FCM server and made our service worker ready to host our awesome custom logic. Like we mentioned, we're about to send web push notifications to our users to expand and enlarge their experience without application. Lately, web push notification is being considered as an engagement feature that any cool application nowadays, ranging from Facebook and Twitter to numerous e-commerce sites, is making good use of. So in the first approach, let's see how we can make it happen with Socket.IO.
In order to make the FCM server aware of any client--basically, a browser--Browser OEM has what we call a registration_id. This token is a unique token for every browser that will represent our clients by their browsers and needs to be sent to the FCM server.
