How to show Notification at specific time ANDROID studio?

Question

Java

Hello kind people. I rummaged through almost everything, and it seems that there is an AlarmManager and a NotificationManager for this .
BUT, either my hands are NOT growing from the right place, or everything that I found is not relevant since API 29 .
The task is that at a certain point in the day, when the application is closed, a notification (with sound) is displayed. Like an alarm clock, but here the user does not have to select the time (it is always the same, which, in theory, should simplify the code).
Could you paint the teapot how it should look like. I will be very grateful!

Answer 1

Make your service . And already from the application running in the background, show a notification at the right time.

Answer 2

Google workmanager