How do I make Salesforce fields available when creating a template or document?

I would like to make an Account field available to me when creating a document (or template) in PandaDoc.  I have gone into the Object Configuration, chosen the field in the Account  and THEN chosen the field (prefaced with Account ID.) in the Opporunity tab.  I do not see the field as available to me when creating a document.  What am I missing?  What makes fields available for selection in PandaDoc?