As an alternative - I will explain what we ended up doing.  I don't like using QB Desktop invoices for tax returns as we use QB for time tracking, so it creates an entry for every bit of time logged.  Yes, you can aggregate them by item code, but I still like to see the detail internally if I want to look back at the bill.  So we prefer to use Lacerte invoices for presentation purposes for tax returns.  Our work around to get payment was to create a standard payment authorization .pdf.  Then we upload that with the DocuSign as an additional document to sign with each DocuSign request.  We set up some customized fields for things like name, amount, routing number, account number, date, signature field, etc. (which the Lacerte DocuSign process allows you to save so you can use it from one client to the next).  My admin staff drag and drop the customized boxes onto the .pdf each time (takes 30-45 seconds per return).  Then we get back a signed authorization to process their payment.  We don't offer credit cards and just offer bank transfers since the cost is vastly different (flat $3 for a bank transfer).  When we get the DocuSign back with the signed authorization we then go into "Receive Payments" in QB and enter the info. under e-check and it processes and applies it against the invoice and the funds are automatically deposited.