Where Do You Get the Code for Activating YouTube on Your TV?
Get the activation code for the YouTube application on a television by first signing in to a YouTube or Google account on the television and then visiting YouTube.com/Activate. Select the account to be used if prompted, and then enter the activation code from the YouTube application.
Signing in to the YouTube application on a television or other streaming media player requires a Google account associated with a YouTube channel. When signing in to the YouTube.com/Activate webpage, the site displays all of the Google, Google+ and YouTube accounts associated with the email address used to sign in. Once the activation code from the app has been entered, the YouTube application displays a confirmation screen and is ready for use.