Hey, i am kinda "new" to spigot peogramming, and i wanted do connect my Chat plugin with Luckpers. i e. I want to get the prefix from the User/group.

Hwo do i do this?

I have no clue!

I use Eclipse and i dont know how to "connect" the API to Eclipse.

Use the Vault API instead. That’ll mean you automatically support any permission plugin that supports Vault too (essentially all of them) and using it is easier and a lot more streamlined for chat plugins. And there will be a lot more people being able to help.

The API documentation is available here: https://github.com/lucko/LuckPerms/wiki/Developer-API

Unfortunately, I can't provide general programming help. You can search online for how to import other jars into your Eclipse classpath.