Why would you want to connect a Playbar to the USB port on your TV? USB audio outputs are not commonly used on TVs.

Why don’t you tell us what TV and we can hopefully set you straight on connecting it.

I’m sorry I posted it wrong, I’m wanting to hook up to the HDMI eARC port on a new Vizio TV, I have a older Sonos playbar that only connects with the optical cord, I was told by the Vizio tech that if I could connect to the eARC port the tv would recognize the device and I would be able to adjust the volume with the Vizio remote! 
I got on the phone with a Sonos tech and was told the Vizio remote uses infrared and the bar recognizes Bluetooth. 

Connect the Playbar to the TV’s optical audio port. Then setup the TV remote to control the Playbar by following the steps in this article:

https://support.sonos.com/s/article/3402?language=en_US

Not sure the tech has it right.  The Playbar is infrared or WiFi, not Bluetooth.  But there is no way to connect the Playbar via eARC, it only connects via optical, which the Vizio should have.  Then, if the remote is infrared, you can setup the Playbar for the remote in the Sonos settings for that room under "Remote Control Setup".

You are correct, the Bar recognizes WiFi, but the TV will only recognize the sound bar through eARC, and the Vizio remote uses infrared.

By the way the sound bar had been connected to our Samsung TV, and I can still control the volume on the sound bar with the Samsung remote! I’m just trying to get it to connect to the Vizio remote 

And I have it connected to the Vizio optical port and it’s working fine, just not able to control the volume with the Vizio remote. 

You need to setup the remote control on the Playbar.  See this link:

Control Sonos home theater with your TV remote

Jgatie you were spot on, I wasted several hours trying to figure it out with Sonos & Vizio techs, and within 2 minutes I had it corrected using the link you provided. Thank you so much!