I need to file an extension but haven't received one of my W-2's and do not have old pay stubs. How do I enter the amount of 2018 taxes I've paid if I can't get the info?

You can use your 2017 tax return to estimate.

Here is how to get an extension using TurboTax:

1.     Open your return in TurboTax Online.
(To do this, sign in to TurboTax and select the Take me to my return button.)

2.     Select File an extension at the bottom of the column on the left side of the screen.

3.     If you don't see the File an extension button in Step 2 above, search for extend in the upper right and select the Jump to link at the top of your search results.

4.       Follow the onscreen instructions to e-file your extension. 

For more information and the source, follow this link: How to File an Individual Extension