I can't think of another type of connection that could be other than toss link.
Strange that it doesn't have a cover though.
There are cheap converters that you can buy that will convert HDMI to RCA though.
New TV With an Unknown Audio Out Jack?
I have an older Zvox tv base sound bar only has coaxial RCA & Toslink optical digital inputs. I would like to use it with a new 2023 TV however the TV only has an one that I think I can use. It is the one to the left, square with a star hole. Is that a Mini-Toslink output jack?