[techsupporter]

> You can block gift cards in most payment gateways, I imagine you could do similar with Apple's system.

What GP means is to go to a grocery store and lay out 10 American Dollars for an Apple-branded services gift card (what used to be called an iTunes Gift Card). One of these: https://www.apple.com/shop/gift-cards

You apply it to the brand new Apple ID you've made and use those virtual funds to make the in-app purchase in the Twitter app that, at the time, was the method of paying for Twitter Blue. (The purchase page even said/says, "You can only subscribe on the Twitter iOS app (for now).")

No blocking of prepaid or gift cards here; you're doing exactly what Apple wants and it's not Apple's problem that Twitter takes IAPs for a "verified" service.