A real iPhone is required (XS or later). The Simulator cannot read a contactless card.
The app currently on the phone must be a new Nimbill binary that includes Stripe Terminal. The old App Store / Expo Go install does not have this code until you ship a new TestFlight or EAS build.
Expo Go cannot do NFC Tap to Pay. Use TestFlight, an EAS preview build, or eas build --profile development-device.
Stripe Checkout (type card on screen) works on that same real iPhone as soon as Stripe keys are on the tenant — no Apple entitlement needed.
Physical tap of a plastic card needs Apple Tap to Pay on iPhone entitlement for App Store, plus Stripe Tap to Pay enabled for the UK account.