How to connect directv receiver to audio sound bar through the digital audio jack on the back of the receiver

I'm trying to connect my Samsung Sound bar to receive audio input directly from the back of my C4W1-100 wireless receiver. The projector I use doesn't have digital audio, so I can't plug my sound bar into that. The problem I am having is that even though I have my receiver connected to the sound bar, there is not audio output from it. The receiver still transmits the audio through the projector via hdmi.

Why is that?