How to make a chat rank for everyone ? (without group)

With OnPlayerAdded, add a string value to them with their rank, then have your chat script handle whatever you have it do to display their rank in chat.

And when i go search chat rank (no group) i have results but all the results is named "chat"

And i want to add the rank to a when a new player join

I gave you the answer to your comment question in my very first comment.