How to wake up an app at a specific time in IOS

I need to run a task at a specific time (for example 2 hours later) in Flutter, something like an alarm, I have searched in flutter and I know that this is not possible easily.

I have tested work manager and it didn't work properly. I have done the Android Part of the project with Platform_channel and Android Alarm Manager.

I was wondering If you know any other ways in IOS (or Flutter if possible).

• some similar questions were asked before but they are too old (this page and this page) and haven't had any new solution or update since 2014.
• I need to run some code so as far as I know local notification its not the Answer.

EDIT:

My App needs to play a sound (1~3 minutes length) at specific time something like an alarm.

I would check out this question and answer Local notification sound not playing while app in background - Swift. It's not exactly the same as your question but I think you could use the same technique with a little creativity.