digital wallet2 money transfer2 payment gateway2 qr code payment2 qr pay2 virtual card2 contactless payment1 developer api1 ewallet1 flutter app1 flutter app remittance solution1 global payments1 merchant payment1 mobile wallet1 multi currency1 multi-currency1 phone authentication1 qr code money transfer1 qr code wallet1 referral system1 remittance1 sms verification1 user rewards1