critical constant

InterruptionLevel const critical

The system presents the notification immediately, lights up the screen, and bypasses the mute switch to play a sound.

Subject to specific approval from Apple: https://developer.apple.com/contact/request/notifications-critical-alerts-entitlement/

https://developer.apple.com/documentation/usernotifications/unnotificationinterruptionlevel/critical

Implementation

static const InterruptionLevel critical = InterruptionLevel(3);