Here is an answer that might help: https://ttlc.intuit.com/replies/6232912
See this TurboTax support FAQ - https://ttlc.intuit.com/questions/1901031-how-do-i-file-an-irs-extension-form-4868-in-turbotax-onlin...
Full details below:
How do I file an extension?An IRS extension gives you until October 16 to file, but it doesn't give you until October to pay your taxes. Those are still due by midnight, April 18.
(Expecting a refund? You may not need an extension. Read more here.)
Below are 5 different ways to file your IRS extension (click or tap here for info about state extensions).