Press U then click on the Assignments tab. Your requisitioned bridge officers should be there. Double click on them to assign them to their posts.
I was having the same problem until someone in chat kindle explained this to me. I kept looking in my inventory, which is what I think the explanation in the tutorial actually tells you to do, or seems to tell you to do, at least.
It took me a few minutes to discover it, but its not really a bug. Maybe a badly designed UI, but most certainly not an error in the game.
I agree it's not a bug, but I do think they need to change the tutorial because the BOff *does* appear in inventory there. I think they should put it where the BOff's appear the rest of the game and just clearly tell you where to look when you get your first BOff.