Use Apple account balance to make payment on Apple Card

I received $200 to my Apple account for a trade-in when I bought a new phone. I was told I could apply this $200 to my Apple card installment balance, but I see no way to choose this form of payment. How do I apply my Apple account balance to my Apple card installment balance? Thanks! Similarly, I have $61.25 in Apple Cash and can't figure out how to apply that to my installment balance either. Thanks for your help!