Where can I send my payment? I need the physical address.

You cannot pay the Apple Card through Bill Pay.

You need to use one of the payment mechanisms through the iPhone's Wallet App, or online at https://card.apple.com

The physical address for Apple Card payment requires you set up a one time payment with an Apple Card specialist before hand and the process only works once.

click here ➜ How to make Apple Card payments - Apple Support

See the "If your iPhone or iPad is unavailable" section in the link above.

Bill pay payments are not an option. All payment is made in the wallet or at card.apple.com. See How to make Apple Card payments - Apple Support