EssentialsX Chat is an addon for EssentialsX, including most of EssentialsX's chat formatting features. It allows you to customise chat formatting on your server by adding prefixes, suffixes and colours in chat, as well as setting different formats for different groups.
You need a matching version of the main EssentialsX module to use this addon module. You also need Vault and LuckPerms to give players prefixes and suffixes, and to detect groups.