One of the awesome features of the TCL Sound Bar is wireless music streaming. No need to connect another device and you can cast from a mobile device to the sound bar. Below are the step-by-steps instructions:

Power on the sound bar.
On an Android device, open the Google Home app. Note: You can download and install the Google Home app from the Google PlayStore.
It is important that the Android device is connected to the same Wi-Fi network that the TCL sound bar will be connected to.
In the Google Home app, you would be prompted to signed in to your Google account if you haven't yet.
You should see an option Set up SB, then follow the onscreen instructions. If you do not see the setup option, click the Plus + sign on the upper right corner of the app.
Select New devices>Setup new devices in your home, the app should be able to find the sound bar.
Then follow the on-screen instructions to complete the setup process.
Once completed, you can now start casting from your mobile devices.