Hi there!
You need to use my core plugin, somewhere above all Eli Plugins. If you are not using it, RPG Maker Plugin manager will show you an alert message at the bottom of your plugin manager window.
Download here my core plugin:
https://hakuenstudio.itch.io/eli-book-rpg-maker-mv-mz
Thank you! Got it working like a charm :)
Nice! Have fun! :)