Create thumbnails for uploads

It mentions on the site that WP File Manager can create the thumbnails of various sizes as wordpress normally does when uploading to the media library. I selected the preference to upload files to the media library as well, but the annoying thing is that it just copies the images to the normal wp upload folder, just as if I were to upload them through the WP native media uploader. Is it possible for the file manager to upload the file withing the designated file structure, generate thumbnails in the same folder, and register those images with the media library?