Chicago office visa pickup

A friend of a coworker has been kind enough to offer to pick up and hand deliver my visa that just became ready. Before I send them into that mess of an office, I just want to make sure I only need to provide them a letter saying I approve of them picking up my visa and a copy of my ID? That’s what I was told but just want to double check. Also, visa pickups happen at the same office we applied in? Email didn’t share location.