In trying to determine AMT for 2019, turbotaxonline is asking for the "Adjustments or preferences treated as exclusion items" from the 2018 return. Where is that?

[DavidD66]

If you had any AMT preference items on your 2018 tax return, they would be on Form 6251 - Alternative Minimum Tax - Individuals.  If you prepared your tax return using TurboTax in 2018, if the program did not generate a Form 6251, you did not pay any AMT and would not have any preference items to carry forward.