I need to file 2016

TurboTax Online for 2016 is no longer available.  You'll need to purchase the 2016 program from the TT website.  I've linked that page for you below.

https://turbotax.intuit.com/personal-taxes/past-years-products/2016/

You'll download and install the software to your computer and prepare your return.  Once you've finished, you'll need to print, sign and mail your return to the IRS.  Prior year returns cannot be e-filed.  Please remember to sign your return.  I also recommend sending the return via Certified Mail so that you have a signature to prove the IRS has received the return.

And don't forget your state return if that applies to your situation.  If you do have a state return, mail it separately to your state's department of revenue.