Short answer
HubSpot's KB: you need a paid DocuSign plan. DocuSign is a user-level app, so each user connects their own DocuSign user. In settings you add an HMAC security key and map fields so envelopes use contact, company and deal properties. It's not a data sync app that syncs full records to DocuSign.
1. Connected apps
Connected apps in my demo portal.

2. Quotes
HubSpot quotes have their own e-signature. See quotes.