bee_hotel-1.x-dev/modules/beehotel_addtocart/beehotel_addtocart.services.yml

services:
  beehotel_addtocart.addtocart:
    class: Drupal\beehotel_addtocart\AddToCart
    arguments: ['@entity_type.manager', '@config.factory', '@commerce_cart.cart_manager',  '@commerce_cart.cart_provider']