How to Authenticate DocuSign email address in Nintex workflow Office 365

Hi,

I am using DocuSign action in my Nintex workflow, created a new account in DocuSign. 

My issue is as this is the new account I am not sure how can I authenticate the DocuSign account in SharePoint envirnment. I have added action DocuSign send document action, but this action is not sending email to the receiver, Also I have cheched DocuSign inbox for mails, I didn't receive anything there as well. Workflow status is showing sending status from couple of hours, no changes in the workflow status. 

Is there anything that I need to do for DocuSign email address authentication before adding the docuSign action in Nintex workflow? Because in DocuSign send document action, it is asking to add only email address of the DocuSign account called Authorizing user.

Any help is much appreciated.

Thanks, PT