@Override
    protected void handlePermission(@NonNull File path) {
//         Should we show an explanation?
//        if (shouldShowRequestPermissionRationale(
//                Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
//             Explain to the user why we need permission
//        }

        mRequestedPath = path;
        requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);
    }
Request permission to write to the SD-card.
android/modules/module_filepicker/src/main/java/com/nononsenseapps/filepicker/FilePickerFragment.java