Volume control issue

My tv is old. No HDMI CEC. Only option is optical cable for my newer soundbar.

Okay. So I'm in settings on my apple tv 4k. In remotes and devices. At the home cinema control section. I click on Volume Control. I click on Learn new device...

I use the soundbar remote now, righ. I do the volume up, volume down, mute. I give it a name - "Soundbar". I click OK. It tells me Setup Complete.

Big problem though.

The new option isn't there. I have a list that says

"Auto"

"Tv via IR"

"OFF"

That's all it says.

No idea what's going on. Very confused.

I need help.

Please.