Can not install on System/app or System/priv-app

[Mitezuss]

To Reproduce

Try install on System/app or System/priv-app (with permissions)

Expected behavior

Wanna install on System from TWRP

Device info

• OS Version: Android 9
• App Manager Version: 2.6.1
• Mode: root

[MuntashirAkon]

You mean App Manager? There's no point in installing App Manager as a system app because it doesn't declare all the necessary permissions. Even if it did add all the permissions, it would also require permission whitelisting since most system permissions are signature permissions i.e. only granted to apps having the same signature as the android package or having 1000 user ID.