Our price add-ons use draft orders which aren’t compatible with the discount code box on the checkout page.
We came up with an alternate option while we wait for Shopify to make this change.
We worked with KartDiscount to make our apps compatible and allowing you to add discounts on the cart page.
You can check out a working version of this app on our demo site.
Click here to install KartDiscount and add a discount code box to your cart.