Connect to soundbar

I have a Sony TV with very poor sound and no audio output passthrough. My 3rd Gen Apple TV has both HDMI and optical audio outputs. The HDMI connects to my TV for video display and the optical connects to my soundbar for audio.

My Apple TV 4th Gen arrived at it only has an HDMI. How do I get the audio out to my soundbar? Is there some sort of adaptor? My soundbar does not have any HDMI inputs. It only has the TOSLINK optical input and the red & white RCA input.