If you used the TurboTax online editions for tax year 2018 you can download the tax data file and then transfer the 2018 tax data to the 2019 desktop tax return when you start a new return.
To access your current or prior year online tax returns sign onto the TurboTax website with the userID you used to create the account - https://myturbotax.intuit.com/
Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show. Click on the 2018 and Click on Download .tax file