Can i get pop-up notifications on my Moto E4?
Unfortunately there is no option on the Moto E4 in settings to enable these types of pop-up notifications, so you will have to either go into each app (like you did with WhatsApp) and enable pop-up notifications or install an app from the Google Play Store.

An app that I use on my phone is called Heads Up Notifications - https://play.google.com/store/apps/details?id=codes.simen.l50notifications&amp;hl=en