Can't get into Med-Tec's PC - SPOILERS

I just did part of the mission Long Road Ahead with MacCready: killing Barnes and Winlock. MacCready was suppose to give me the codes for the PC at Med-Tec but instead he returned my caps I gave him a while back. How do I obtain Jacob's password?

P.S. I know there is a password called Jacob's Password at the other settlement but that isn't the correct Jacob's Password.