Information like this is usually available on the Sonos website. 

“Sonos Beam connects to your TV’s HDMI-ARC port. Most TVs have two to four HDMI ports, one of which is labelled ARC, which stands for Audio Return Channel. The HDMI-ARC port syncs audio and picture, plus automatically pairs your TV remote to Sonos Beam. If you’re unsure if your TV has an HDMI-ARC port, consult your TV specs with the manufacturer. If your TV is older than 5 years, or otherwise doesn't have an HDMI ARC port, you can use the included optical audio adapter to connect Sonos Beam to the optical port on your TV. Please note that Amazon Alexa TV voice commands will not work when connected via optical adapter.”