Hi, Some on brought me an OEM accessory bed extintion as a gift for my NBS Sierra 08, but it came without any hardware or mounts, ANY ONE installed this beofre? does it come like this or it should have mounts/bolts etc?

and if no thing comes with it, how it should be installed? I cant see any pleace to hook it to, just two ties goes into the tailgate locks, but from inside the bed, where does it fit?