The year you closed your business is the final year of operations. When the business is closed, you should be reporting that your ending inventory is -0-.
So, if you did not sell the inventory until 2020, then you cannot close the business for 2019.
In TurboTax, from the left navigation pane, go to Federal>Income & Expenses>Self-Employment Income & Expenses>Edit/Add to update the activity for the year.
