libreevent can be extended easily with plugins. Plugins add additional features and can be official or community made. When installing plugins, you need to remember that a server restart is required to activate the plugins as libreevent does not feature hot module loading (yet). You then can manage the plugins using their built-in settings page that they ship with.
Please only install plugins from sources you trust!
You may read on about plugins here and you can find an installation guide here.