You can use the interview on the IRS web site below (be sure to select the 2019 tax year) to determine whether or not a return needs to be filed for 2019.
https://www.irs.gov/help/ita/do-i-need-to-file-a-tax-return
If a return needs to be filed for the decedent for the 2019 tax year (i.e., a final 1040), then the person preparing the return using TurboTax will have to use a 2019 desktop product; it cannot be prepared online.
See https://turbotax.intuit.com/personal-taxes/past-years-products/
