API SpecsCartsSubmit active cartCreates an order from the current cart and returns the checkout URL.POST/api/unstable/carts/{handle}/submitTestCreates an order from the current cart and returns the checkout URL.Response Body200application/json400application/json401403application/json404application/json409application/json422application/json503504application/jsonUpdate cart comment PATCHStores or clears the customer comment associated with the active cart.Update cart line item PUTSets the quantity for a single product inside the active cart.