The 2018 AGI is on the 2018 Federal tax return you filed Form 1040 Line 7

The 2019 AGI is on the 2019 Federal tax return you filed Form 1040 Line 8b

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 View adjusted gross income (AGI)

For what tax year?   For your current 2019 return?  Or do you need the 2018 AGI in order to efile a 2019 return?