been a while so I don’t remember precisely which you would use in this setup case.. I would think the USB would be used for the connection to the ps5 in this particular case meaning you’d need the Optical port to RCA cable to make use of it. Then again, PS5 is far far too new to make any calls of certainty from me.
you should be able to find some useful information here as well as you can ask any questions you have about potential setups with your new console.