In this case, your employer isn't required to file a corrected W-2 for 2023.
Your repayment in 2024 is a claim of right repayment. You can only report it in the year you repaid the claim.
If your repayment is less than $3,000, you'll claim it as a Miscellaneous itemized deduction in Schedule A.
If the repayment is more than $3,000, please read this TurboTax Help topic on how to make the claim.