This reject message indicates that the taxpayer on this return has already been claimed as a Dependent on someone else's tax return.
If this is correct and the taxpayer is a dependent, please go back to the "My Info" section in TurboTax and check the box to indicate that "Another taxpayer can claim me as a dependent on their tax return" and then answer "Yes" to Will this person claim you on their 2024 tax return? Once you have done this, you should be able to e-file successfully.
If this is incorrect and the taxpayer is not a dependent, then you will either need to mail in your tax return or go to IRS.gov and get an IP Pin. For more information, please see this TurboTax Help Article: How do I get my 6-digit IP PIN?