Client failed the KBA authentication questions, how do I advise & proceed to get a signature

Trying it again might be an option.

Otherwise, send PDFs of the signature page and tax return to the portal.  Then the client would need to print, sign, scan and upload it back to you.  Or do it via postal mail.

This is still a pertinent question even a year later. 

If you log directly into the linked DocuSign account you can actually resend the envelope I think 2 more times.  I do not recall the menu path for this, but think you need to open the envelope in DocuSign and choose More. 

If you void and reissue the document, in the addressing dialog box, upper right, you may (or may not) for a given client have a PIN option.  I think this is only available if they have passed KBA in the past. 

Another tip, is that you can actually download your competed items from DocuSign as opposed to the tax system (Lacerte for us) which we find faster and easier as we do not need to navigtate away from the tax files into eSignaure