You would not enter anything under IRA contributions, as the reporting is fully handled through the input of Code AA on your W2.Also, that's a Roth 401(k), not a Roth IRA.
As long as your income is low enough, you are still eligible to make Roth IRA contributions. But, you need to do so outside of your employment. What you have done with your job is not an IRA.
https://www.irs.gov/retirement-plans/plan-participant-employee/retirement-topics-ira-contribution-li...
