First be sure you have answered all the military questions in "My Info" section. Next, check your military W2 entries to be sure you have selected "Active Duty Military Pay" in the follow on questions. The information will transfer from those federal answers to your state return and will either automatically exclude the income or trigger any follow questions to exclude any military active duty pay according to the laws of your resident state.
I identified income as active duty military pay on my federal questionnaire but it did not exclude it from my state tax (PA)
If PA is on your W2 in boxes 15-17 then it will show up in the state interview. Edit/continue your PA state interview and when you get to the summary page update the Income and Adjustments section. You will get to a page to verify your W2 income. The PA W2 should be there. You can exclude the active duty military income by checking the correct button on this page.
If PA is not on your W2 then it will not show up in the state interview at all.