Bug Unable to access the device memory

I've come to the conclusion that from Android 10 onwards, even knowing the path to the app's external memory (but internal to the device, not even to the SD), it's impossible to access write, and probably read.
System.IO.File.CreateText that worked at least until Android 8 returns an exception.

 

@JuliusM, I read the article... and the comments about the video on the bottom

I agree!
I tried creating a custom manifest and adding permissions as shown in https://stackoverflow.com/a/64665699 (WRITE_EXTERNAL_STORAGE and READ_EXTERNAL_STORAGE).
I used the function https://stackoverflow.com/a/50688343/17464387
but (after correcting the syntax) it didn't work. What did I do wrong?


Is there any hope that in an upcoming Unity update they will automatically add the necessary permissions to the manifest and the ability to read and write files in any location? If I create a text editor app I need it!