My cash card won’t let me add money to my Apple Pay
I can’t add cash to my Apple Pay using my cash app cash card
iPhone 12 Pro Max, iOS 17
Apple Pay does not hold any money.
If you mean add money to your Apple Cash account (different thing entirely to Apple Pay) , then, as explained in the support document you posted from, you can only do so from a debit card or prepaid cards that are already added to the Wallet App. 3rd party cash apps are not supported.
After you set up Apple Cash1, you can add money to your balance using the debit or prepaid cards that you already use with Apple Pay in Wallet