How to send message to sender via WebSocket?

Question

Java

Hello. I need to issue a response to a specific sender on an incoming message to a web socket. There is the following

the code

@MessageMapping("/terminal")
public void transmitData(@Payload StdInDTO data, Principal user, @Header("simpSessionId") String sessionId) throws Exception{
  StdOutDTO stdOutDto = StdOutConverter.toDTO(terminalService.transmitData(StdInConverter.fromDTO(data), sessionId));
  
  simpMessagingTemplate.convertAndSendToUser("Какой-то пользователь", "/user/queue/", stdOutDto);;
}

How can I identify the recipient of a message so that the message is sent to the sender of the original message?