Apple Pay is not a Green Dot bank. It isn't even a financial institution, online or otherwise.
Apple Pay is payment mechanism that uses NFC terminals to pay in stores.
Green Dot Bank is a supported bank to add cards to Apple Pay from. However adding funds to Apple Pay cash requires a debit or pre-paid card. It does not work with Credit cards, and not all prepaid or debit cards may be supported.
Add money to Apple Cash - Apple Support
- You can't use credit cards with Apple Cash, and you might not be able to use some prepaid cards. You can't add money from a gift card, even if it's already in Wallet.