Follow this guide to properly install ChatPlugin (free version) in your server(s).
Download the plugin's last JAR from SpigotMC, Bukkit or my website if you haven't already.
The free version does not have BungeeCord support. You can only install it on a Spigot server. To do it, simply put the downloaded JAR in your server's plugins folder and (re)start the server. Please note that reloads are supported, but you cannot overwrite a JAR (if there was one already) while the server is running: doing so will cause lots of errors and no support will be given. Once the server has started correctly all configurations files should have been created and loaded.
Data storage is handled by a database created by the plugin. There are currently two supported database engines: H2 (recommended) and SQLite. The premium version offers MySQL support, too. You can choose which one to use editing
storage.method in config.yml. You can also choose what folder to save the files in and the database name. Encryption is not supported yet but it will be added soon. A plugin reload is necessary to make effective any change made to the database settings.
To update the plugin to a newer version, follow these steps:
The plugin should print some info saying that the configurations' defaults values have been set; you won't lose any setting: the new default values required for the newer version to be run have been simply added to the file.