Is it possible to set up an Apple Savings account without upgrading my iPhone to iOS 16?

The situation: I've got an Apple Card set up, and I'd like to also open an Apple Savings account (to get 4.15% interest on my spare cash), but the button to do that doesn't appear unless you've updated your phone to iOS 16, which is a problem because apparently Apple doesn't support iOS 16 on my iPhone 6s+ (it is updated to iOS 15.7.5, which it assures me is "up to date"). My question is: is there any way for me to set up an Apple Savings account without having to buy a new iPhone? Perhaps there is a web-based method available somewhere?