Get a Coaxial audio digital to analog converter. Convert the Coaxial Audio out to RCA with an active converter.
Something like this https://www.amazon.com/Musou-Digital-Optical-Converter-Adapter/dp/B01AWBA8U8/
Like this?
https://www.amazon.com/Musou-Digital-Optical-Converter-Adapter/dp/B01AWBA8U8?th=1