const userSocketMap = {}; io.on(“connection”, (socket) => { socket.on(“register-id”, (username) => { userSocketMap[username] = socket.id; console.log(socket.id); }); socket.on(“sendingMessage”, (data) => { const { sender, receiver, message } = data; const receiverId = userSocketMap[receiver]; if (receiverId) { console.log(data); io.to(receiverId).emit(“receiveMessage”, data); } else { } }); }); server.listen(3000, () => { console.log(`Server running on http://localhost:3000`); }); here […]