Have you already paid for the online product? We can tell you how to reach TurboTax Support to ask them for a solution. See if they will provide you a download. The 2 products have different pricing structures, so I'm not sure how they handle that.
Once it's solved, you can download the *.tax2016 data file you started online and continue and finish it in the desktop software without starting over. We can tell you how to download the *.tax2016 file that is in progress. See this on how to move the file:
https://ttlc.intuit.com/questions/1901476-how-do-i-switch-from-turbotax-online-to-the-turbotax-softw...
FAQ: How do I contact TurboTax?
https://ttlc.intuit.com/replies/6386875
