Can they sleep in this??

So I have a baby due 2/4 and we’ll be moving about 3 weeks after that..

Right now between my son and daughter and my SO and I it’s going to be tight with an added crib or pack n play.

My question is.. how safe are these to sleep in? I’ve never owned one but just got one like this as a gift. Would it be safe to sleep in for like 3 weeks? Or would baby be too squished?

Thanks in advance!