How to set priority for data message? [Flutter]

[mateoKutnjak]

I need to set priority of the data message to 'high' because terminated Flutter app will ignore it otherwise. I tried fcm_devices.send_message(None, extra=json_message, priority="high"). It works when app is in foreground and in background but not when it is terminated and it has to be because of priority: https://firebase.flutter.dev/docs/messaging/usage#message-types

Edit: I need pure data messages (no notifications)