There should be some directions on your TV when you go to the Netflix app. The main thing is, getting the activation code and going to movies.netflix.com/Activate to activate that particular TV. Once you do that, you should be good.
Restart your TV and look for the booklet. EIther you Google or just try opening the app on the TV and see where the activation code is being sent. The key is to activate the code and your Netflix will start working. usually, this doesn't happen as once clicked on the Netflix app on your TV the app asks for login credentials and it starts working