Retirement tax questions

On the screen where you enter your sales transaction details, there is a check box for:  "I have other boxes on my 1099-B to enter".  Checking this box will reveal more entry options, one of which is "Federal Income Tax Withheld".  See screenshot below.  If you don't want tax withheld, you can contact your broker to see about what forms need to be filed so that your aren't subject to tax withholding.