Dvd sound only comes through headphones

[Machine]

Just picked up a 2011 Nissan Pathfinder. Still trying to figure everything out. My question is.....how can I get a dvd to come through the speakers? I can only hear it through headphones. I tried hitting the headphone button...it keeps saying “no rear controls availableâ€. So I hit the rear control button and it said the same thing. What am I missing?? Thanks.