Hi,
I just posted the Gift Card option to my store as an additional Product. Does anyone know a way to exclude Promo Code discounts from being used to PURCHASE the Gift Card? I don’t mind if the recipient of the Gift Card also uses a discount code, but I don’t want to SELL the Gift Card at a discount - thus having a discount both on the front & back end. Would love to hear if anyone has faced this same issue and if you figured out a solution.
Thanks!
I’m also looking for a solution for this .
Late response here and you probably figured this out by now, but in case someone else finds this…My understanding is that gift cards are automatically excluded from discounts for the reason you stated. 
But to your broader point, it would be nice if there was a way to automatically exclude a new product or collection from existing discounts without having to modify all existing discounts. If anyone knows how to do that please let me know.
Unfortunately, this is not true. I created a sale and when I added the gift card to the cart to test, it does apply a discount. 
I have to agree with @Nourishe it wont apply discounts for gift cards on mine either - maybe you’re on an older version of Shopify? Or using a third party discount app?
As of Nov 12, 2024, you can use the HideOperation in the Payment Customization Function API to disable native gift card functionality and Shopify-integrated third-party gift card systems. Disabling gift cards hides the gift card field, removes any applied gift cards, and prevents any gift cards from being applied by UI extensions.
The ability to disable the gift card field is available in the unstable API version and will be released to the stable 2025-01 API version.
You can also find apps on Shopify App Store Click to find
Thank you