If you want to use the smart features of Alexa to control your TV, then follow these steps to complete the setup:
Your computer should have the webOS operating system or higher.
Install Alexa App on your smartphone form the Play Store or App Store.
Launch Set-Up TV for Alexa App from the home screen of the TV.
Then use your TV remote and go to the Extra Bar on the menu.
Then in the voice settings pair your TV with Alexa and Echo device.
Now, you can use Alexa to control your TV. In case, these are confusing you then take help from the Amazon Echo Alexa helpline number

Read more - Echo Show Phone Number