For future people finding this, the rules did not change between 2018 and 2019. You must enter the parents AGI in specific cases. For example if your dependent earned more than $2,200 in unearned income (as of 2022). This could happen if the dependent had a stock account for one possibility. If you are required to enter the AGI, TurboTax will ask for it. You won't need to search for it.
