Add a friend on Binance: First complete identity verification for your Binance account (chat and private messaging features are unavailable until verification is complete). Then open the chatroom in the Binance app (tap the “Messages” icon/chat widget on the home page, or search for “Chatroom” in the search bar). On the chat page, tap [+] in the top-right corner → select [Add Friend], then enter the other person’s UID.