Did you make a payment with the extension? If not, you do not enter anything in your tax return about the extension. The IRS knows that you filed an extension.
If you made a payment with the extension, you have to enter the payment in TurboTax. Type "estimated tax payments" (without the quotes) in the Search box, then click the link that says "Jump to estimated tax payments." That takes you to the screen that says "Estimates and Other Income Taxes Paid." Scroll down a little to the second section, "Payments with Extension." Click the Start button for "Payment with 2023 federal extension."
If you do not have a payment due on your tax return, there is no penalty for late filing.