Have you visited Binance. Where to buy crypto with master card, visa, or by p2p. Perhaps many other exchanges can also buy crypto with a master card, or by means of a bank transfer.
First, Binance.com blocked all the US customers from using the platform so this is not possible
Second, Binance.us, the Binance alternative exchange that US customers use does not have XRP listed in the platform, so a gain, no way of acquiring XRP from there
OP has other options
1. Use p2p trading platforms
2. First buy BTC and Create an unverified account on an exchange using VPN, transfer the BTC to buy XRP he needs and withdraw it into an external wallet. Of course withdrawals have to be below the daily withdrawal limit for unverified accounts in an exchange.
This is a risky move though.