While the items are being placed on the register cart, can I have a separate process that adds custom items to it ?
Example: Add milk, Add coffee, jump to another app that will add another custom item, jump back to the register and customer pays.
From what I can see, while you are adding items to the cart, the order hasn’t been created yet (or saved). Is that correct ? Is there any api that let me add items to the cart from an external app ?