Because there isn't a way to update your prior-year tax software to handle the 2020 tax laws, you'll need to purchase TurboTax 2020 if you want to use TurboTax to prepare this year's taxes.
In addition, we have to stop supporting old operating systems (for example Windows XP and Mac OS X v10.9) when their manufacturers no longer support them either. These kinds of structural program changes cannot be handled in an update.
Welcome back! And thanks for choosing TurboTax.