Welp my guess is it will work like Apple Pay. They've just announced they would allow apple pay to work outside of Apple devices/browsers by showing you a code you could scan with your iPhone to pay for shit through Apple Pay.

But 2030 is too far in the future, so we don't know how much freedom of implementation is in the banks for their customers and payment providers like Stripe for the merchants and how janky the whole shtick will be.