How do I apply my daily cash to my balance owing

Note especially these steps when making a payment. Once you establish Apple Cash as a payment method, that choice will remain if effect for future payments (barring a Reset action on your part).

1. Open the Wallet app on your iPhone and tap Apple Card.
2. Tap Pay.
3. Choose a payment amount and tap Pay [amount].
4. Tap your bank account, then turn Apple Cash on.

You may then need to tap the Back button, then authenticate with Face ID, Touch ID, or passcode to make a payment.

See “Pay with Apple Cash or a different bank account“ here.

How to make Apple Card payments - Apple Support

You’re welcome. Glad it helped. Enjoy your Apple gear.