I am trying to activate my TV on my account but cannot seem to find the right option on my TV?

As per Sony instructions I need to navigate to SEN and 'link account'.  Issue is, I don't have the option of linking an account?  I didn't even have SEN on the menu at first so, the steps I have taken are thus;

• signed into Google account to allow the addition of the SEN
• select add account (takes me straight to Sony sign in which then adds SEN to the menu)
• now when I navigate to SEN the only options I get are to either sync or remove.

If I select sync, nothing happens and I certainly cannot see how I get an activation code from anywhere to link to my account?