How to restore access for applications on iPhone 7
Applications have lost access to the phone's resources. The options for granting access have disappeared in the settings. You cannot give permissions to: contacts, camera, iCloud Drive, calendar, microphone, photos, ... This applies to, among others: WhatsApp, but also the Support app from Apple (problem with the calendar). (Maybe it's a coincidence, because the phone has been damaged for a long time and does not support traditional calls using a SIM card).
[Re-Titled by Moderator]
iPhone 7, iOS 15