Only your 2018 return can be prepared using the current online software. Each tax year must be prepared separately.
Online preparation and e-filing for 2017 is permanently closed.
To file a return for a prior tax year
If you need to prepare a return for 2015, 2016, or 2017 you can purchase and download desktop software to do it, then print, sign, and mail the return(s)
https://turbotax.intuit.com/personal-taxes/past-years-products/
Remember to prepare your state return as well—if you live in a state that has a state income tax.
When you mail a tax return, you need to attach any documents showing tax withheld, such as your W-2’s or any 1099’s. Use a mailing service that will track it, such as UPS or certified mail so you will know the IRS received the return.
Note: The desktop software you need to prepare the prior year return must be installed/downloaded to a full PC or Mac. It cannot be used on a mobile device.
You are asking from TT Live, for which you are paying extra:
https://ttlc.intuit.com/questions/4124827-how-do-i-connect-with-a-tax-expert-in-turbotax-live
This service is only available for 2018 returns.