Generating UPI Request ID
The merchant should generate upiRequestId following these criterias:
upiRequestId should be an alphanumeric 35 length string.
It should start with a 3 character prefix which is given by NPCI for every handle. Example: "AXBfcd764aeab2a4bd195b25d652c1887f7" where AXB is the prefix.
Code snippet for upi request id generation

