How to know if a user has received a notification?

My app sends users notifications of important messages in the app. How can I make sure the user receives them?

Did you look at this (notificatiosns with actions): https://developer.apple.com/documentation/usernotifications/handling-notifications-and-notification-related-actions

You would know if user has tapped a button (AFAIU, not if he simply discarder the notification or did not see it)

How to know if a user has received a notification?
 
 
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