Invalid request hash, please check request parameters

so I trying to test a money transfer with pagaBusinessClient.moneyTransfer() but I keep getting the invalid request hash.

I have already generated a sha512 using the format e.g (referenceNumber+amount+destinationBankUUID+destinationBankAccountNumber+hashkey) as it was in the documentation. then I passed the hash as 'hash':hashvalue in the headers request.

Is there something I am doing wrong?