Pack N Play bassinet for nighttime sleep question.

I have been assembling my pack n play, and everything has gone well but the bassinet is making me feel like an idiot. It says that I can use it for night time sleep but as you can see in the pictures, there is no way to remove the part that is used for strapping the baby in. I can remove the whole soft part of the bassinet but then it is just a piece of hard plastic. I can't find a Pack n Play bassinet mattress, and it's not like my baby is going to sleep strapped in (I'm sure the straps are for seated positions). it is also way too bulky to put the baby just on top of where the straps are. it seems both uncomfortable and a hazard. anyone else use this bassinet or something similar to it or is just a smarter person than I am that can give me some advice?

here?