Install PIX for tvOS
Open the App Store
Open the App Store from your Apple TV and select the Search tab.
The App Store isn't available on Apple TV 3rd Generation or earlier.
Search for PIX System
Hold the Siri 
speaker button to dictate and search for PIX System.
Alternatively, you can use your Siri/Apple TV Remote or Apple TV Remote App to type in the PIX System.
Note: Head to Apple's direct website to learn more about how to Use your Siri/AppleTV Remote or how to Use the Apple TV Remote App.
Get PIX
Navigate to the PIX app icon and click "Get" to download.
Once the app has downloaded, click "Open" to launch PIX.
Going forward, you can find the PIX App on your Home screen