How to grant su permission to app after unroot?

Question

What I want:

I want my app to use su command to take screenshot in background even after I unroot the phone.

code example:

val process = Runtime.getRuntime().exec("su")
val outputStream = OutputStreamWriter(process.outputStream)
outputStream.write("/system/bin/screencap -p\n")

What I tried:

I thought I will just root my phone and install the app in priv-app folder and then unroot but it's not working like that.

How can I do this?

Answer 1

It's impossible to grant root access after unrooting. You can give fake root access in termux but it just shows #. So no use.