How to Share DTO Across Spring Boot Microservices?

@RestController
@RequestMapping("/users")
class UserController {

    private UserService myUserService;
    private RoleService myRoleService;
    private Mapper myMapper;

    // Constructor

    @GetMapping
    @ResponseBody
    public List<UserDTO> getUsers() {
        return myUserService.getAll()
          .stream()
          .map(myMapper::toDto)
          .collect(Collectors.toList());
    }


    @PostMapping
    @ResponseBody
    public UserIdDTO createUser(@RequestBody UserCreationDTO userCreationDTO) {
        User user = myMapper.toUser(userCreationDTO);

        userCreationDTO.getRoles()
          .stream()
          .map(role -> myRoleService.getOrCreate(role))
          .forEach(user::addRole);

        myUserService.save(user);

        return new UserIdDTO(user.getId());
    }
}

public class UserService {
    public UserDTO getUserById(String userId) {
     
        User user = userRepository.findById(userId);
        
        // Convert User to UserDTO
        UserDTO userDTO = new UserDTO();
        userDTO.setUserId(user.getUserId());
        userDTO.setUsername(user.getUsername());
        userDTO.setEmail(user.getEmail());
        
        return userDTO;
    }
}

public class OrderService {
    public void placeOrder(UserDTO userDTO, OrderDTO orderDTO) {
        // Convert UserDTO to internal User object if needed
        User user = new User();
        user.setUserId(userDTO.getUserId());
        user.setUsername(userDTO.getUsername());
        user.setEmail(userDTO.getEmail());
        
        // Process order
        // ...
    }
}

public class CustomerDTO {
    private String firstName;
    private String lastName;
    private String cardNumber;

    public CustomerDTO(String firstName, String lastName, String cardNumber) {
        this.firstName = firstName;
        this.lastName = lastName;
        this.cardNumber = cardNumber;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }

    public String getCardNumber() {
        return cardNumber;
    }

    public void setCardNumber(String cardNumber) {
        this.cardNumber = cardNumber;
    }
}

// Original code snippet
String serviceUrl = "http://localhost:8002/order-service";
OrderResponse orderResponse = restTemplate.postForObject(serviceUrl + "/create", 
  request, OrderResponse.class);

// Modified code snippet with explanation
String myServiceUrl = "http://localhost:8002/order-service";
OrderResponse myOrderResponse = restTemplate.postForObject(myServiceUrl + "/create", 
  myRequest, OrderResponse.class);