I filed federal extension through TurboTax Easy Extension. Now I am finishing up my tax return, I need the federal extension confirmation number. Where can I get that?

There is no such thing and you do not need it to file.

As Critter#2 said, there is not a federal confirmation number that you need in order to file your tax return.  Just file it normally.  But check to make sure your payment was entered.

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 

Some states require that you either send a copy of the Federal extension request, or indicate the state extension confirmation number.