Notifications center

Notifications of WhatsApp are not iOS dependent.

Notifications use Wi-Fi only when a cellular connection is unavailable. Firewalls and proxy servers might affect your ability to receive notifications. Get help using Apple Push Notification service (APNs). 

If you don't see notifications for a specific app

To get notifications, connect to a Wi-Fi or cellular network. If you still don't get notifications for a specific app, try these steps:

1. Make sure that the app supports notifications. Go to Settings > Notifications, select the app, and make sure that Allow Notifications is on.
2. If you have notifications turned on for an app but you're not receiving alerts, you might not have Banners selected. Go to Settings > Notifications, select the app, then select Banners.
3. Make sure that you’re signed in to your Apple ID. 
4. Make sure that Do Not Disturb is off. 
5. If you’ve recently installed an app or restored from a backup, open the app to start getting notifications.

WhatsApp is not an Apple product. Contact the app developer here --> App Support

Facebook is not an Apple product. Contact the app developer here --> App Support

Delete WhatsApp and reinstall it. When you start setting it up again, it should as you if you want to enable Notifications. Say "yes".