In order for Lightspeed to facilitate costs for line items like coupons, shipping, or taxes, you'll need to set up a product for each non-inventory item. This article will go into greater detail about why this is, and what your options are for these products.
Shipping & Coupons
Lightspeed calculates shipping costs, coupons, and taxes as separate line items on orders. To make this work with your integration, you'll have to create three products: "Coupon", "Shipping", and "Tax". These products can be created as non-inventory items, and they don't need to have a specific price. After they've been created, please enter the SKU for each in the form attached to the relevant onboarding task. This will allow Modern Retail to make sure they're appropriately configured.
If you have any further questions, please feel free to get in touch with your Project Manager using the messaging feature in the Onboarding Center.