Hi @Cheryl H,
Welcome to the Sonos community and thanks for bringing this to our attention. Let me share some information to help you out.
The usual setup that works for your devices is that your AppleTV should be connected via HDMI to your TV, and your Playbar is connected to your TV with the optical cable. Is this how your AppleTV and Playbar are connected?
Can you get audio from your TV to your Playbar? If this is the case, you may need to check your AppleTV audio settings and set it the same input as your TV audio settings. Sonos home theater products like the Playbar supports these audio formats - Stereo/PCM and Dolby Digital 5.1/AC3. I'd like to share this thread that might help you out with other settings and configurations.
Please let me know if you have any further questions or concerns, we’ll be glad to assist you.