Messages tab: direct messages, group chats and club conversations
(use the Message button on a club's profile). The + New button starts
either a DM or a group (name + members).
Group admins can add/remove members; anyone can leave.
Block a player from a DM header to stop messages both ways. Report an
abusive message from the message itself — moderators review it.
Stickers: the 🎾 button next to the message box opens your sticker library. Upload your own (WebP, PNG or GIF — made in any sticker app), file them in folders you name, and save a sticker someone sent you with its ⋯ menu. Animated stickers need the latest app version on the phone.