Can minors chat or talk with other users on Kluppy?
No. There is no chat or messaging between users on Kluppy. No student can write to another, send them anything, or contact them in any way. That feature does not exist.
The only thing one user can see of another is their public alias and their score on leaderboards and duels. Nothing else: not their real name, nor their email, nor any contact details. That is why you search for friends by alias and not by email.
And if you still prefer to disable it, you can block social features in the parental controls: the friends list and duels will disappear completely.
In the extracurricular activity, there is indeed a chat, but it is between the family and the school or instructor, within the family portal. Never between students.