how to add a screen when the screen is off like the default alarm screen when the alarm ring with flutter, alarm screen is not its not coming

Question

how to add a screen when the screen is off like the default alarm screen when the alarm ring with flutter alarm screen didnt coming even with out without lock screen.

in without lock screen its opens the app and when lock is enabled then its open in background first you have to open the lock. please check the code

https://github.com/jja08111/flutter_alarm_app/

https://github.com/bastokr/flutter_alarm_app