You have most probably accidentally created a loyalty program coupon code.
If you accidentally created a coupon for a set amount of points and you didn’t end up using this discount because, you didn’t want to or you have used another coupon instead, you can use this coupon later. Your points have not been lost and the coupon code is accessible through the Loyalty Program widget for you to use at any time.
You can access the Loyalty Program widget, shaped like a present, in the bottom right on the website (non checkout pages). If you click the widget (while signed in) and then select “My Rewards" you can view all the coupons you have created in the past. Just view one and copy the discount code and put it in the discount section on the checkout page.
NOTE: Points discounts can’t be used with other discounts.