post https://payment-api-service.transactpay.ai/payment/order/pay/authorize
Note that you'll need to input the "Pin" parameter on the /pay endpoint.
Afterwards, an OTP will be triggered to the payer and the "orderPaymentReference" from the call to the /pay endpoint will then be inputted.
{ "orderPaymentReference": "PGW-PAYREF-8148A99542E64F5BA1FB1C47E0D4D74F", "otp": "614145", "message": "" }