With the plugin WP DISPATCHER you can create an temporary and secure download link for your file uploads. Your uploads are secured in a special folder. The secure download links are created by shortcodes which you can use anywhere. Every shortcode call generates a new download link so be cautious where to use it (best suited within automatic emails).
First upload your files to a secured folder. Then generate expiring links to your protected uploads. Usage with wp shortcodes.
Caution: Files are protected via .htaccess. This works only in LAMP environment with Apache as Webserver.
Create a Pull Request against a new branch on Github: https://github.com/ekntrtmz/wp-dispatcher
Copy newest version into trunk and commit changes to trunk.
Copy trunk to a new tag with semver. Push changes to new tag.
Examples: https://developer.wordpress.org/plugins/wordpress-org/how-to-use-subversion/#examples