Not sure why you want that. You do not need it to file now. If the IRS received your 4868, they know you have an extension. There is no place on the Form 1040 to enter that you have an extension and you do not have to include another copy of it with your return.
You do have to make sure that you have entered any payment you made at the time you requested your 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
Just complete the preparation of your Form 1040 as normal. You have until October 15 to use online TurboTax and to e-file the return. After that, online and e-filing will close down and you will need to use the CD/download software on a full PC or Mac, and file by mail.