ELS-Plex-Generator is a Plex-specific add-on tool for Entertainment Library Synchronizer (ELS), available at https://github.com/Corionis/ELS, that generates the publisher library JSON file required for ELS.
ELS-Plex-Generator queries a Plex Media Server (PMS) directly using the PMS REST interface, typically on port :32400, to gather the necessary data.
A PMS X-Plex-Token is required for authentication, see Finding an authentication token / X-Plex-Token on the Plex support site.
This software is written in Java and operates on Windows, Linux, and Apple systems.
See the project on GitHub at https://github.com/Corionis/ELS-Plex-Generator or the ELS Plex Generator Wiki with How To information at https://github.com/Corionis/ELS-Plex-Generator/wiki.