I'm doing my 2018 income tax return. The app says I paid $4,564 in 2018 which I did not, but I don't know how to delete it. Is it importing it from the previous year?

[VolvoGirl]

Does it show up as an extension payment or as estimated payments?  What line on the 1040?

You can preview the 1040 or print the whole return

https://ttlc.intuit.com/questions/1901539-how-do-i-preview-my-turbotax-online-return-before-filing