Zoho sign scopes in authtoken

Zoho sign scopes in authtoken

Hi,
I would like to create an authtoken for ZohoSign (I would need just to read the signed documents) but I cannot create the authtoken, I always get INVALID_API_AUTHTOKEN_SCOPE error. 
I'm making a HTTP Post to:
https://accounts.zoho.com/apiauthtoken/nb/create?SCOPE=ZohoSign/signapi&EMAIL_ID=******@*****.it&PASSWORD=*******&DISPLAY_NAME=*** 
Obviously the scope is wrong so which are the scopes in the ZohoSign?

Thank you