I am being asked to enter 2019 AGI. For 2019 taxes, I was a non filer and provided my info to the irs for the stimulus. Should I select that I didn't file last year?

If you filed as a non-filer, answer that I have my 2019 tax return. You 2019 AGI is $0.  

Additional information: How do I find last year's AGI?

Thank you for your response! Should I put $0 for AGI, even if I had income (income below the threshold that requires you to file)? Additionally, what number is the non filers form, because I am required to state which form I filed last year. Thanks again for your time.

Yes, The answer to all of that is that you should enter zero.  Whether you filed as a non filer, didn't file or filed under the income threshold, they would all be zero.

Thank you, I am required to declare which form I filed. Would I say that I filed 1040 or something else? 

Since you did not actually file a tax return, go back and select that you didn't file last year and put in zero for the AGI.

If you used the NON filer option last year to get the stimulus money  then your AGI IS on the return.  If you entered NO income then your AGI is $1.  If you entered some income then LOOK at the form 1040 line 8b.