Reward-Redemption-Token
set to the coupon code. Thanx will find
the matching reward and update it.
When you send Thanx the provided code with the basket contents, Thanx applies
the configured discount logic and responds with an appropriate discount
(or an error message). The POS then applies the discount (or displays the message).
Finally, when the check is paid out, a final API call is made to finalize the purchase.
This marks the reward as used. See more details
on Loyalty API /Create Update Basket.