Some previous replies have been correct. This used to be a feature of the desktop version. It has now become hard to find. I agree in that we shouldn't have to switch to using online account. Also, the Search function points towards the old way of doing it: Search "extend" and then pick on "Jump to extend". This no longer works!
I did find a way to do it on the desktop:
Save the Return and exit Turbotax.
Restart Turbotax.
The first screen is "Continue Your 2024 Tax Return". I my case, I have two returns (mine and my daughters) to pick from. I didn't pick either yet. In the lower-right corner you find a button for "File an Extension". Pick that and Turbotax will walk you through filing the Federal Extension. I chose to pay an amount. It adjusts for that in the "Federal Tax Due" amount at the top-middle of the screen, so the system understands I am making that payment. I also checked the forms to see if it updates that payment, which it did on Schedule 3, line 10, carried on line 31 of form 1040. Bravo!
Unfortunately, I couldn't find a way to get it to do my State (Arizona) extension. I had to download the form, fill it out, and mail.
