To verify your employment you have to first log on to Ultipro. On the front page, there is a FAQ link for InVerify that walks you through the signup process. Follow those directions. (Here is specifically where you sign up: https://inverify.net/ManageIncomeKey.aspx).

Basically you create an account and then the person who requires verification logs in and "pulls" your information using your SSN and Income Key. However, I'm not sure how much luck you're going to have asking the parking office to go through this. I tried to see if I could pull an unofficial copy for myself but it wouldn't even let me register so I gave up.