transfer function
transfer( responseBack, payercustomerId, payerpI, payeemsisdn, txn )
| Name | Type | Description |
| responseBack | Indicates which function to be called when a response is received. | |
| payercustomerId | The customerId of payer | |
| payerpI | The paymentInstrumentId of payer | |
| payeemsisdn | The msisdn of payee receiving the payment | |
| txn | The TxnData object that contains txn details |