You do not mention what kind of dependent you have or what refund you are hoping for. There are two kinds of dependents--qualified children and qualified relative dependents. If your dependent is a qualified child, you might get refundable credits like earned income credit or the additional child tax credit for a child under 17. Or if the dependent is an "other" dependent, you might get the non-refundable $500 credit for other dependents, which can lower your tax.
Dependents are added--or edited -- in MY INFO.
Wait until your original return has been fully processed before you amend, and make sure you have saved a pdf of the original return before you amend. (If you do not save it as a pdf, the amended return will overwrite the original, and the original will be lost forever)
See this TurboTax support FAQ for amending a tax return -
CURRENT YEAR
Do not expect quick results from amending. It can take four months or more for the IRS to process an amended return.
You can watch for information here:
https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1
WHO CAN I CLAIM AS A DEPENDENT?
You can claim a child, relative, friend, or fiancé (etc.) as a dependent on your 2024 tax return as long as they meet the following requirements:
Qualifying child
Qualifying relative
When you add someone as a dependent, we'll ask a series of questions to make sure you can claim them. There may be other tax benefits you can get when you claim a dependent.
Related Information: