"Add to Pardot List" button not available

Hello,

Apparently there is a button that can be added on the Lead and Contacts tabs in Salesforce called "Add to Pardot List." When I check the available buttons in the Mobile and Lightning Actions section, it isn't there.  I can't find it in any other sections on either the Leads or Contacts pages.

We have Enterprise Edition of Salesforce and use Pardot. Is there a reason that button isn't available?  Anything I need to check or set?

Thanks.

#Pardot B2b Marketing Automation  #Pardot Salesforce Sync