In my opinion based on my experience, don’t expect to get approved.
Even if you get approved, don’t expect much performance.
Gift cards, are allowed, here is an example, when it is allowed, if you the merchant are selling a clothing line, then offer a gift card.
What is mostly not allowed, if your main business, is just selling gift cards.
Instead of shopping ads, instead use text advertising in Google Ads. Which does not require the same level of policies.