Can't find 'Cast' button in Netflix app
If the "Cast" icon is missing when you try to watch Netflix on your Chromecast, it's usually because it isn't on the same network as your mobile device. If you can see and tap the Cast icon, but your Chromecast or TV doesn't appear, follow these steps instead.
If you're on an ad-supported experience, you won't be able to use your TV as a display for Netflix content playing on your mobile device (casting or mirroring).
If your account isn't on an ad-supported Netflix plan, follow the steps below to fix the problem.