In most cases, you do not need to do anything to file your 2020 taxes because of a 2019 IRS letter. The exemption—the IRS has questions about something on 2019 that is being used for 2020, such as an unused deduction or credit that is being carried forward or a depreciation expense.
We can't help unless you know exactly what the IRS is asking for.
Your IRS letter will give you instructions on what to do. You can call the number on your letter and ask whether this will affect your 2020 filing.
If you purchased Audit Defense for 2019 contact them at 877-829-9695 or at intuit.taxaudit.com.
TurboTax offers free audit support. Your Tax Expert will probably ask you to read or show them the letter. Otherwise they won't be able to help you. What is the TurboTax phone number?