Directly on your 2020 tax return. When you go through the federal review tab it will ask how much you got if any. Or to enter your stimulus payment in TurboTax, type "stimulus" (without the quotes) in the Search box, then click the link that says "Jump to stimulus."
After you have entered your tax information and are ready for the Federal Review, it will be the first question.
If you are trying to trigger it, you can go to Other Situations, answer any questions and click Done. The next automatic selection is Federal Review and it will ask about payments received.
You are an Adult child? How old are you? If you are under 19 or a full time student your parents can probably still claim you no matter how much you made.
Under the CARES Act, if you are claimed, or qualify to be claimed, as a dependent on someone else’s return you were not qualified for a stimulus check, in 2020. If you qualified as a dependent for 2019, but will not be for 2020, you will most likely get it in 2021, when you file a 2020 tax return.