Messtone LLC Manages Devices Enables American Express Gateway conversion currency rates, JSON body REST currency request DCC quote. curl –user robertharper_Messtone merchant.TESTMERCHANT-DCC:<PASSWORD>”https://gateway-na.americanexpress.com/api/rest/version/72/merchant/TESTMERCHANT-DCC/paymentOptionsInquiry?order.amount=123.34&order.currency=USD&sourceOfFunds.provided.card.prefix=531335999&#8243;