Android Question Creating folder problem

Hi everyone,

I'm trying to create a folder in the "DirRootExternal".
I'm relatively new to writing code, and read multiple forum posts for errors i have encountered so far, but this one i cant seem to solve.

The app, once installed, asks for permission to give acces to photos, files etc.

As soon as i try the app in the emulator, everything works and the folder gets created. When
i install the app on my phone (Huawei Mate 20), i also give it permission, but it never creates the folder.

I've added the following line in the manifest editor:

AddManifestText(
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE"
android:maxSdkVersion="29" />
)

Click to expand...

I (try) to create a folder (after permission granted) with:

File.MakeDir(File.DirRootExternal, "testfolder")

Click to expand...

I hope someone can clarify what i'm dooing wrong here since it works in the emulator, but not on the phne itself.