Go to Deductions & Credits.
Select I'll choose what I work on.
Scroll down to Employment Expenses.
Click Start or Update by Job-related Expenses.
Work your way through the screens till you get to one that says Job-Related Expenses.
You must have more than 2% of your adjusted gross income in these expenses, plus a total of more than your standard deduction, to write them off.
See below for your standard deduction.