Getting the client brand of the client

So, I want to identify if a player is using Lunar Client. I figured that the custom_payload packet is the one I’m looking for, so I try to research this and can’t find anything.
This is the packet I’m trying to read:


is there any way to get the data from this packet?
I have tried https://jd.velocitypowered.com/1.1.0/com/velocitypowered/api/event/connection/PluginMessageEvent.html