Add thumbnail in media library ?

Hello,

that’s not how this plugin works, but there is a hook, that you can use to do whatever you need, even. eg. add images into the library…

There is no documentation for that, but it’s a pretty clear and not-so-long code, so take a look on that do_action( 'pdf_thumbnail_generated', $new_filepath, $pdf_id );

I’m pretty sure that any good WP programmer will be able to implement this for you.