[Plugin: Download Manager] Indexed by search engines?

I have a very simple setup with no WP membership and a private page as setup through the “Visibility: Password protected” for a single page. A group of users is given the single password and has access. I installed the plugin and set the access to all with no password. Am I correct in saying that someone cannot find a link to the file(s) (hotlink). Also, are the files indexed by search engines?

https://www.ads-software.com/extend/plugins/download-manager/