Shares were sold by my ins co. I rec'vd proceeds less backup withholding due to issue with W9. In reporting 1099-B how do I claim backup withholding to get it refunded?

My insurance company was bought and shares were sold. I received a check for proceeds of the 2018 sale, but due to an error on Ins company's brokerage, they claimed they did not have my W9 on file so backup withholding was deducted from my proceed check and sent to the IRS. They state I need to simply report the 1099-B and the funds withheld in backup withholding will be refunded to me, but there is no place to list the Federal income tax withheld (box 4 or form 1099-B) on turbotax..Help? How do I report box 4 Fed Income tax withheld.