I have a product to which 100% discount code has been applied. This product can only be redeemed by the customers who have received their discount code prior they visit the store. Users will be redirected to the product page via the main page.
Once they are on the product page, they will enter the discount code, the product will be available for free and they will proceed with check out.
This product should only be available for redemption via the discount code and not for sale.
How do I make the product available only via redemption checkout and not through normal sale process?