I noticed that your question has gone unanswered for a few weeks which can occur for a few reasons. Generally, questions that are thorough, clear, and contain screenshots/packaged workbooks are the most likely to receive responses. Keep in mind that sometimes even great questions fall through the cracks. If you are still experiencing the same issue, I recommend re-commenting on the post with more information or contacting email@example.com.
P.S. If you have found a solution to the issue, feel free to post it as a response to the thread. You may end up helping another user with the same issue.
The extract API access only local files. You can retrieve workbooks and data sources from the server using the REST API or tabcmd, unzip and get the tde file then append new data with the extract API