This is pretty inexpensive:

https://www.amazon.com/avedio-links-Extractor-Splitter-Converter/dp/B093H3GFR3/ref=asc_df_B093H3GFR3/?tag=hyprod-20&linkCode=df0&hvadid=693308325757&hvpos=&hvnetw=g&hvrand=3418144480195832381&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9020608&hvtargid=pla-1431579157864&psc=1&mcid=82cf41a6f2bc32ec8292bc0b0ba24b57#customerReviews

May be just what you need.

@RWE2173 

The hdmi audioextractor @Pools-3015 mentioned will work fine for audio from devices connected to its hdmi in, but is limited to only one hdmi in. There are such devices supporting more inputs, but you have to connect all your source devices like set top boxes to the switch/ audioextractor instead of to the tv. 
And… if you like to get audio also from your tv (internal apps or linear tv) the hdmi out of the audioextractor has to be ARC ready and be connected to an hdmi ARC input on tv. 
 

If your tv supports a coax spdif digital out for audio and supports passthrough of multichannel audio from connected hdmi source devices, the better solution imo would be a simple coax to optical converter. 
This one is a bidirectional…

https://www.amazon.com/dp/B07BSBMZT7/ref=mp_s_a_1_7?dib=eyJ2IjoiMSJ9.Y0muf6eCeCHNRU7L6Glz6yGKC2Vpae2fPG0lHYO9XTRrcIPvs9J4rv3ehFi_3VSoH0smASWgAhzMhaMTBNtsoqzwktKEQajWhwQYuq7m_e3LDZGmkrRYKvIXYRO6s23TBzI_8h63lG08cauwf4D0nU6OOtZgUT5Xbf_oO1S9Zjf7wcx7Cg5fhNaRDDIwsr8Gn73Zopm6v45eXbI1P_ksbA.AU96JYs7Y1zyw9ofulLie3q5W_Ib3N7lWkrD97oPErQ&dib_tag=se&keywords=coaxial+to+optical+converter&qid=1726006177&sr=8-7