Dodawanie oferty up-sell

https://www.youtube.com/watch?v=GTArgkjUv9w&list=PLqWPuXFMCdRr75ghxzagrkG35k_Ke-3lh&index=20

https://scribehow.com/shared/Dodawanie_oferty_up-sell_dla_ceny__9BDaR4qrQZascLGtaKFpbQ