My app is simple

1. Take Time from the user(I know how to do it)
2. schedule A notification(I know how to send notification)
3. Now I just want to know that How can I send this notification even user removes it from recent apps.

Tried Solutions-
AlarmManager, BroudcastReceiver, Service, Intent Service,

But all are work only when the app is present in RAM (recent apps list Of Mobile).

How can I do that just tell me the topic. I don't need code.
I will study that.