TurboTax is not a tax return preparation service for prior year tax returns. You can use the TurboTax desktop editions to complete and file a tax return.
For prior year tax returns, 2016 thru 2018, you would need to purchase, download and install on a personal computer one of the desktop editions for each tax year needed to a personal computer, Win or Mac, from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
Prior year tax returns can only be printed and mailed, they cannot be e-filed.
If you was assistance from a Tax Expert or CPA with completing a 2019 tax return you will need to use one of the TurboTax Live editions - https://turbotax.intuit.com/personal-taxes/online/
See this TurboTax support FAQ for Expert Review - https://ttlc.intuit.com/community/expert-review/help/what-s-an-expert-review-in-turbotax-live/01/27498