Get soundbar audio

Both devices should have an optical audio port according to their respective specs sheets --- so buy an optical audio (Toslink) cable and connect them together with that. Cable like this:
https://www.amazon.co.uk/AmazonBasics-Digital-Optical-Audio-Toslink-Black/dp/B00L3KO5WK/ref=sr_1_2_sspa?ie=UTF8&qid=1548771685&sr=8-2-spons&keywords=audio+to+optical+cable&psc=1

From the picture of the optical cable above, you should easily be able to identify the location of the optical ports on TV and sound bar, or check the user manual for each device.