The extension form thru TT would look like this one from the IRS and it would not say it was filed anyway ... you can fill it in and print it and give it to those fools. https://www.irs.gov/pub/irs-pdf/f4868.pdf
What you really want is the filing history showing an extension was filed and accepted ... of course it will not say what was on the form only that one was filed. If you really want proof it was filed you should get an account transcript from the IRS. https://www.irs.gov/individuals/tax-return-transcript-types-and-ways-to-order-them
Your return's electronic filing status history records all
e-filing activity related to the return, including the Electronic Postmark. You
can print it out if needed.
TurboTax Online
https://shop.turbotax.intuit.com/efile/efile_status_lookup.jsp --
enter the Social Security number of the first taxpayer on the return and the
ZIP code to retrieve your filing status history.
TurboTax CD/Download software
(Windows) From the TurboTax File menu, select Electronic Filing > Show
Electronic Filing Status History.
(Mac) From the TurboTax File menu, select Check E-Filing Status.
