You need something like this to convert the optical output on the TV to use with the mixer.

https://smile.amazon.com/ROOFULL-Digital-Converter-Toslink-Optical/dp/B07142SV1D

Then a cable like this to plug it into the mixer

https://smile.amazon.com/Splitter-Smartphone-Computer-Speakers-Amplifier/dp/B0829VWPSB?th=1