You'll need to purchase and download the TurboTax software for PC or Mac as TurboTax Online and the mobile app are only available for the current tax year.
Please see the TurboTax FAQ below for additional information:
that link is to buy software to file taxes. I already filed them with you last year for 2018.
To access your current or prior year online tax returns sign onto the TurboTax website with the User ID 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 Year and Click on Download/print return (PDF)
If you used the desktop CD/Download editions installed on your computer, the only copy of your tax data file and any PDF's will be on the computer where the return was created. TurboTax does not store online any returns completed using the desktop editions.