I have an Android 7.0 test device and my APK targets = \"targetSdkVersion 22\", with:
If you target SDK 29 and you still get a "permission denied" error after successfully requesting the WRITE_EXTERNAL_STORAGE permission you should add
android:requestLegacyExternalStorage="true"
to the application definition in AndroidManifest.xml.
...
see https://developer.android.com/training/data-storage/compatibility