I just cleared and reapplied the prefix but the prefix doesn't show in chat.

LuckPerms doesn't format the chat for you - you need to install a chat formatting plugin.

I'm not aware of one that exists for Nukkit. Is there a standard API to provide prefix/suffix data, like Vault for the Bukkit project?

p.s. I try to keep the issues on GitHub free of questions - and tend to close such tickets as soon as an answer has been given. We have a Discord server which you might find to be a better place to ask questions.

thank you for replying after my two other non-relevant issues, and i will be on a lookout for a plugin like that.