You would have to print and mail the Form 4868 extension request to the IRS when using the TurboTax software.
The IRS does not send a confirmation of approval but will mail you a rejection letter. So if you do not receive a rejection then the extension was approved and you can file the 2020 federal tax return at any time up through October 15, 2021.
Any federal taxes owed must be paid on or before April 15, 2021 to avoid a failure to pay penalty and interest owed on the unpaid taxes.
When I requested an extension in TurboTax, the instructions show I don't have to file until 10.15.21. However, TurboTax didn't provide me a printed extension form to mail and today is the 2021 normal tax filing deadline. With this particular return, no taxes are owed and no refund is owed by the IRS or state. I'm looking for guidance into how I can confirm if I am ok with sending in nothing today to the IRS and just proceed with filing by October 15 2021? Any feedback is greatly appreciated.
I'd recommend you e-file an extension (you can request an extension as many times as you like).
See Can IRS extensions be e-filed? for help in filing an extension.
There are two ways to file an extension using TurboTax online programs: an e-file extension and a printed extension that you have to mail.
If you did not print and mail a Form 4868, then you may not have finished the extension process.
If you e-filed the request, you should have gotten a confirmation from Turbotax.