The requirement to access a prior year online account is to use and pay for one of the 2018 online editions of either Plus, Deluxe, Premier or Self-Employed. Since you purchased the desktop editions you will need to contact TurboTax support so they can assist you in accessing the 2017 online account and download the 2017 tax data file.
Use this website to contact TurboTax support during business hours - https://support.turbotax.intuit.com/contact/
Support can also be reached by messaging them on these pages https://www.facebook.com/turbotax/ and https://twitter.com/TeamTurboTax
