*On iPad* Apple Card billing address is not updating

Solution (in broad steps)

1. Confirm that the Billing Address for Apple Card is correct under Settings -> Wallet & Apple Pay [Payment Cards -> Apple Card. If it isn't one can correct it there.
2. In Settings -> Apple Account (which is what you get by tapping on your name) -> Payment & Shipping -> Apple Card. (This is where I had the wrong billing address and no option to edit.)
3. Remove the Apple Card from payment methods. (You probably need to leave at least one payment method in place at any one time)
4. Turn the iPad completely off and reboot it. (I found this step to be necessary)
5. After restarting the iPad go back to Apple Accounts -> Shipping & Payments
6. Add back your Apple Card.

Without Step 4, I found that the old billing address remained. There may have been other ways to do this, but that is what I found.

It appears that I misunderstood my situation. When I follow those instructions, I see that the card already has the correct billing address. Where I am seeing the wrong billing address for the Apple Card is under

Apple Account -> Payment & Shipping [Under Payment Methods] -> Apple Card [under Billing Address]

Now that I have a better understanding of what has my old address, I will try to get that updated correctly.

Thank you. The solution (or a solution) was that after removing the Apple Card from Apple Accounts -> Payment & Shipping, I needed to turn my iPad off and back on again. Then when I re-added the card, it had the newer billing address.

I have no idea if any of this actually matters for things, but I had noticed that on my iPad, my Apple Card had not been showing up as an Apple Pay option in actual use. So I wanted to tidy up all of this stuff before diving into that issue. Next time I try to use Apple Pay to pay for something from my iPad, I will see if getting this all cleared up helps.