If you have a single member LLC and you report income on a Schedule C on your personal return, you don't need to mark anything final on your tax return.
However, you can indicate in TurboTax you ended the business. Navigate to Federal > Wages & Income > Self-employment income and expenses Add/Edit. Select the business, choose Edit. Scroll to Business Summary, select the pencil to edit Your business name's info. Under General info, select Edit under Stopped work in 2024 to change to Yes.
