unless you live in certain counties in California with an automatic extended due date, your return is due today. no additional extensions. if you file after 10/16 and owe there will be penalties and interest for both late filing and late payment. if you don't owe, there will be no penalties for filing late. Beware there could still be penalties for underpayment of estimated taxes which is a different penalty from those for filing/paying late.
If you are due a refund you have up to three years from when the Federal return is due. That means you can file this return with a deadline date of April 18th 2026. If you owe and don't pay by October 16th 2023 you will be penalized plus interest the longer you wait. When you filed for the extension to October 16th 2023, then you should have paid the taxes you owed at that time. Otherwise you will be penalized and charged interest for money you owed when due on April 18th of 2023. When you are getting a refund the extension is for three years without a penalty or interest. If you file late then use the Turbo Tax for the year the tax is due even its three years late. If you owed Federal tax on April 18th 2023 then you have already accrued a penalty and interest starting at this time. If you file past the October 16th 2023 deadline you may have to mail your return.