DocuSign Account Needs to be Created for Each Buyer for Signing?

Summary

DocuSign Account Needs to be Created for Each Buyer for Signing?

Content

Hi - Below is the scenario.

1) DocuSign Admin Account created with the user name "[email protected]". 
2) Set up the task "Configure Electronic Signature for Procurement Documents" with user name and password and Account id etc information.
3) Email id ("[email protected]") with which DocuSign admin account was created, assigned to the Buyer (Say Buyer1).
4) "Buyer1" Logged into Fusion application, can create PO and Send for approval.
5) PO got approved and status changed to "Pending Signature Preparation".
6) Buyer1, from the action - select "Prepare For Signature".
7) DocuSign UI opened and without any problem, Buyer1 added recipients for Signing. So far all went fine as expected.