why i dont receive notifications

Notifications or Notifications Alerts?

1. Help for Notification Alerts --> No Notification Alerts - Apple Community
2. To turn ON notifications selectively for apps, go to Settings > Notifications > Scroll Down to the App and turn ON notifications... Change notification settings on iPhone - Apple Support (IN)
   1. 
3. Some apps have their own notification settings over and above the iOS notification settings: An example of Instagram Notification settings is given below
   1.