How do i amend my 2024 return i just filed? Forgot to add my 1099-SA

It is too soon to amend a 2024 tax return.   You have to wait until it has been fully processed by the IRS.  Sometimes the IRS catches and corrects mistakes you made.   And the Form 1040X you will need is not available until mid-February.  Amending too soon can cause confusion and long delays.

You first need to wait until the return you filed is processed and you receive your refund if applicable before you amend your return, as mentioned by @xmasbaby0 . Once the amend return option is available in TurboTax, you can amend the return to see if the Form 1099-SA has an affect on your tax. If not, then you don't need to file the amended return.

If you used the money distributed from your health savings account for qualifying medical expenses, then the proceeds are likely not be taxable.