hose is a twist on lock fit over the nubs on the side of the waste outlet
sounds like you are missing the fiting on the end of the hose
or somebody broke the end off of the outlet
this is a picture of a 45 degree adapter that has clear insert so you can see when your tank is flushed clean
but what i want you to see is what each end looks like
the claws on the left should be on your hose
the nubs on the fight side should be on your dump fitting
your hose or his adapter locks on to the dump fitting
the claws lock on to the nubs
if your dump fitting does not have these nubs, you need a new fitting attached
if your hose does not have the claws you need a new hose