As far as I can tell there is no way to programmatically apply a gift card by code to the cart using the POS extension APIs.
This is important to us because we keep track of gift cards customers have previously redeemed points for and want to give merchants quick access to them via POS.
Yes, it gives an “Invalid discount code” error every time you try to apply a gift card code as a discount with the addCartCodeDiscount method.
I’m assuming this is because POS handles gift cards separately as a payment step instead of a discount like checkout does. Is that correct? Is there any way around this?