Move 3rd party app to system app

Hi.
I want to move 3rd party app to system app. The purpose is to keep the app even i format/factory reset my phone/ add a new user to my phone.

Phone already rooted (magisk).
Make sure:
1) it works in multiple user.
2) it can be used when added to magisk denylist
Device: Oneplus 8t
Android version: 11

***Don't want to use systemizer (i already try with this but it didn't work with my situation).

Thanks.