How can I get a document that verifies I got an extension

[xmasbaby0]

https://ttlc.intuit.com/questions/2879424-how-do-i-print-my-4868-extension-form-after-e-filing-it-th...

[BMcCalpin]

"How can I get a document that verifies I got an extension"

If I understand the thrust of your question, you don't. The IRS does not send you a confirmation that you received an extension; the presumption is that if you created and filed form 4868 correctly and in a timely manner that you received the extension.

This is one reason that taxpayers are encouraged to e-file when possible or if mailing, to retain at least a "proof of mailing" (not the same as proof of delivery), to show that you mailed something to the IRS on that date (you can handwrite on the receipt what the mailing was for).

If you filed the extension through TurboTax, follow xmasbaby0's advice above and print off the 4868. I don't know if TurboTax has a screen that states that you filed the extension when you re-enter the return a second time ( @xmasbaby0  do you know?), if so, screen print a copy of that, too, and add it to the 4868 for your "proof of extension". 

[xmasbaby0]

@BMcCalpin If I understood your question, no, there will not be a screen that gives the user a way to show that they filed an extension as they are completing the return.  If the user requested an extension then the IRS "knows" they have an extension.  The only other "special" thing to make sure of when completing the return is to see if the estimated tax paid with the extension request has been entered onto the tax return

PAYMENT WITH EXTENSION

When you requested your extension you were supposed to pay your estimated tax due.  Did you enter the payment you made into your tax return?  Go to Federal>Deductions and Credits>Estimates and Other Taxes Paid>Other Income Taxes

[dmertz]

Confirmation that the IRS received a request for extension would be in the individual's Tax Account Transcript:  https://www.irs.gov/individuals/get-transcript