2018 Form 1040 Line 22 for the federal taxes owed.
To access your current or prior year tax returns sign onto the TurboTax website with the userID you used to create the account - https://myturbotax.intuit.com/
Scroll down to the bottom of the screen and on the section Your tax returns & documents click on Show. Click on the Year and Click on Download/print return (PDF)
See this TurboTax support FAQ for accessing prior year online tax returns - https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-access-my-prior-year-return/01/270...
If you used the desktop CD/Download editions installed on your computer, the only copy of your tax data file and any PDF's will be on the computer where the return was created. TurboTax does not store online any returns completed using the desktop editions.
Or go to this IRS website for free federal tax return transcripts - https://www.irs.gov/individuals/get-transcript
For a fee of $50 you can get a complete federal tax return from the IRS by completing Form 4506 - http://www.irs.gov/pub/irs-pdf/f4506.pdf
Look at your account for 2018---it will tell you, although TurboTax never knows if, when or how you paid tax due. it will show how much you owed when you prepared the return. Or look at the tax return Form 1040 itself. Federal tax due on a federal 2018 Form 1040 is on line 22.
You can get a free transcript from the IRS:
https://www.irs.gov/individuals/get-transcript