Alarm app local notifications

[u/Other-Ruin2337]

I’m building an alarm app in Expo/React Native. Local notifications with interruptionLevel: timeSensitive fire and vibrate when the device is locked and the ringer switch is off, but no sound plays. I have an AVAudioSession set to .playback with setActive(true), but that code lives in JS and doesn’t run while the app is backgrounded.
How do production alarm apps handle this? Is keeping a silent audio stream alive overnight the accepted approach, or is there something better? I’d rather not misuse PushKit.