PromotionController.java

@RestController
public class PromotionController {

  private final PromotionService promotionService;
  
  @Autowired
  public PromotionController(PromotionService promotionService){
    this.promotionService = promotionService;
  }

    @PostMapping(value = "/promotions")
    public void perform() {
        this.promotionService();
    }
}