How can I file 2017 returns with 2018?

[DoninGA]

The TurboTax online editions are only for tax year 2018.  

To complete a 2017 tax return using TurboTax you would need to purchase, download and install on a personal computer one of the 2017 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/

A 2017 tax return can only be printed and mailed, it cannot be e-filed.

[SweetieJean]

You need a computer (not a phone) to file 2017.