STP please Come in

I use my OPT work for 3 month. I need to ask for my SSN and Medicaid refund.
I alreday finished my ragular tax return, (1)so I remember you posted I should
use form 823 to get the refund? is it right?
(2) do I need to attach my status proof like OPT card copy? Or how the IRS knew I am in F-1 status? Many Thanks.