This is a plugin that I wrote myself, and he not only handles the chat level but also implements sound effects and so on, and supports All of Minecraft version.
Commands/Chatlevels help are used to display the help menu, which can be used to add experience and /Chatlevels reload Reloaded the plugin.
Chatting with players will give them experience, and reaching a certain amount of experience will automatically increase their level
Finally, I will give you a Chinese configuration file