it's a fine question, but I don't know the answer. In any case, it belongs in the server admin forum, so I will move it there.
Licensing questions are a little tricky to answer without knowing more details and the confidential nature of product keys doesn't facilitate a lot of troubleshooting in the forums. If you are talking about added capacity keys, those might work to activate the Tableau Server but just to be sure, I would recommend reaching out to your sales rep or checking in the customer portal for the actual key and use that one. You can also contact customer service using our contact page: Contact Us | Tableau Software
Hope this helps!