You can delete your account and all of its data directly in the app:
Everything: your profile, email address, activity history, palette and custom activities, follows and close-friend grants, reactions, and day summaries. There is no recovery. Combined world totals contain nothing that identifies you, so there is nothing to remove there.
Email support@kuuluu.app from the address you signed up with and we'll delete the account for you within 30 days.