How can I check to make sure I said yes to "can you be claimed as a dependent on someone else's return"?

If your parents claim you as a dependent in 2024, then you should indicate it on your own tax return.

In TurboTax Online, when your enter your personal details in the My Info section, on the page titled Let's check for some other situations, put a check mark on Another taxpayer can claim me as a dependent on their tax return and click Yes on the question  Will this person claim you on their 2024 tax return? (see attached screenshot).