or download this
my $user_string = 'VendorTxCode=TxCode-1310917599-223087284&Amount=36.
+95&Currency=GBP&Description=description&CustomerName=Fname Surname&Cu
+stomerEMail=customer@example.com&BillingSurname=Surname&BillingFirstn
+ames=Fname&BillingAddress1=BillAddress Line 1&BillingCity=BillCity&Bi
+llingPostCode=W1A 1BL&BillingCountry=GB&BillingPhone=447933000000&Del
+iveryFirstnames=Fname&DeliverySurname=Surname&DeliveryAddress1=BillAd
+dress Line 1&DeliveryCity=BillCity&DeliveryPostCode=W1A 1BL&DeliveryC
+ountry=GB&DeliveryPhone=447933000000&SuccessURL=https://example.com/s
+uccess&FailureURL=https://example.com/failure';