What selection do you mean? 

When setting up the “external Speaker” on the LG, it asks to set the IR blaster to control the “audio amplifier”.  Then, it has a list of all the audio amplifiers to control.  It does not list SONOS.  Is there a better way to set up my PlayBar?

I have a TIVO for the video, the LG TV, and the Playbar.

Currently, when I change the sound or mute, I get an error from the tv saying “cannot control your audio amplifier. Try setting up audio amplifier”.  I still control the sound, but the error message is a bit annoying.

Thank you for your help.

Have you installed the Playbar on your network? Which version of the app are you using?

On the LG, set TV Speaker to Off (page 30 in the manual). Connect the tv optical out to the Playbar optical input. Set TV Autoplay in the Sonos app.