I can’t inject dependency in mapper, what’s wrong?

@Mapper(componentModel = "spring", uses = { UserMapperHelper.class })
public interface ReminderCreateMapper {
    @Mapping(target = "id", ignore = true)
    @Mapping(source = "userId", target = "user")
    Reminder reminderCreateDtoToReminder(ReminderCreateDto dto);
}

@Mapper(componentModel = "spring", uses = {UserService.class})
public interface UserMapperHelper {
     User toEntity(Long userId);
}

@Service
@Transactional(readOnly = true)
@RequiredArgsConstructor
public class UserServiceImpl implements UserService {
    private final UserRepository userRepository;
    public User findById(Long id) {
        return userRepository.findById(id).orElseThrow(() -> new RuntimeException());
    }
}

But
java.lang.NullPointerException: Cannot invoke "ru.lebedev.reminder.mapper.UserMapperHelper.toEntity(java.lang.Long)" because "this.userMapperHelper" is null

I tried to use mapstruct map an id to an object
but it does’t work.