The blue thing is not attached to the drum. Here's a picture showing the adjuster at the bottom. Thete is a slot on the bottom of the backing plate. Stick your screwdriver in and rotate the star screw to close the shoes together.
Drums get stuck. After you move the adjuster in, beat on it. It will eventually come loose.
Thanks for the picture, that helps, I will adjust the brakes with a screwdriver tomorrow. Sorry about sounding simple about the blue center cap, but with my picture I thought it would help to point it out to get help.