Swipe down from the top-left corner of the screen to open Notification Center
Lock your iPhone and wake it to see notifications on the Lock Screen
Check notifications on the Lock Screen by swiping up if needed
Open the app that sent the notification to view in-app alerts
Go to Settings
Tap Notifications
Select an app to make sure notifications are allowed
Turn on Allow Notifications
Make sure Lock Screen, Notification Center, and Banners are enabled
Check Focus mode and turn it off if notifications are being hidden
Make sure Do Not Disturb is not enabled
Ensure your iPhone is connected to the internet for app notifications
Update the app if notifications are not appearing
Restart your iPhone if notifications still do not show