Note: This method accepts custom idempotency key generated by your system. By default, if not specified, it will create one on your behalf.
BeneficiaryAccountNumber is an 8-digit OneKhusa merchant account, not an external bank or mobile wallet account. Prefer a 5–12 character alphanumeric SourceReferenceNumber. On success (S100), use TransactionReferenceNumber for later lookup; CollectionTransactionReferenceNumber may be empty and BeneficiaryMerchantAccountNumber may be 0.