If the TurboTax program is preventing you from continuing with (or e-filing) your return, you can leave Box 9 blank (this may require you to delete the Form W-2 and re-enter it in the W-2 interview - How do I delete forms in TurboTax Online?)
Please click the link below for the IRS article regarding the verification code.
https://www.irs.gov/individuals/w-2-verification-code
