Thank you for your contribution.
However according to Google it is not recommended to open an app automatically at a given time, see also https://developer.android.com/guide/components/activities/background-starts
Android 10 (API level 29) and higher place restrictions on when apps can start activities when the app is running in the background. These restrictions help minimize interruptions for the user and keep the user more in control of what’s shown on their screen. In nearly all cases, apps that are in the background should display time-sensitive notifications to provide urgent information to the user instead of directly starting an activity.
Also starting from Android 10 the app must have been granted the SYSTEM_ALERT_WINDOW permission by the user to be able to restart itself from the background. And in Android 11 this has been even restricted further.
PS: I recently released an alarm manager with notification extension, which currently works only in MIT App Inventor, because Kodular stil does not support the Android X libraries, for more information see here App Inventor Extensions: Alarm Manager | Pura Vida Apps