Sending to individual socketid in Socket.IO

// sending to individual socketid (private message)
io.to(`${socketId}`).emit('hey', 'I just met you');

// WARNING: `socket.to(socket.id).emit()` will NOT work, as it will send to everyone in the room
// named `socket.id` but the sender. Please use the classic `socket.emit()` instead.

References
https://socket.io/docs/emit-cheatsheet/