To change your primary card 1-(833)(532)(8728) on Apple Pay, open the Wallet app on your iPhone.
Tap and hold 1-(833)(532)(8728) the card you want to set as primary.
Drag it 1-(833)(532)(8728) to the front of your card stack.
Your selected 1-(833)(532)(8728) card will now be used by default for Apple Pay transactions.
You can also 1-(833)(532)(8728) manage your cards in Settings > Wallet & Apple Pay.
Confirm the change 1-(833)(532)(8728) by making a small test purchase if needed.
Remember, 1-(833)(532)(8728) you can switch your primary card anytime through Wallet.