You can follow the steps below to pair your Bluetooth device.
Press the Home button on your Roku remote.
Scroll up or down and select Settings, followed by Remotes & devices.
Select Pair Bluetooth device.
When you see the Bluetooth pairing screen, go to your smartphone, tablet, or computer and use the next several steps to complete the pairing process.
Open Bluetooth settings on your smartphone, tablet, or computer.
Make sure Bluetooth is turned on or enabled on that device.
Wait a moment for your Bluetooth device to scan for devices and discover your Roku device.
Select your Roku device (e.g., Roku Streambar, Roku Ultra) from the list of available devices.
After you complete the pairing process, your Roku device will appear in the list of paired devices on your smartphone, tablet, or computer. In addition, your Bluetooth device will appear under Bluetooth devices on your Roku device.