Where do I file form 2678 in my refund?
Unfortunately, Form 2678 is not supported by TurboTax software. You would need to print out the form from the IRS website and mail it in.
For the form to print out: https://www.irs.gov/pub/irs-pdf/f2678.pdf
Where to mail form: https://www.irs.gov/uac/where-to-file-your-taxes-for-form-2678