Showcase your tvOS app in action by bringing its features and functionality alive with a short video on the App Store for Apple TV. By providing an app preview, you can help customers better understand your app and encourage more downloads.
App previews on Apple TV can be watched by selecting the preview button on an app’s product page. To capture footage of your tvOS app, connect your Apple TV to your Mac using a USB-C to USB cable, and use QuickTime Player as a video recorder. Make sure to record your video in landscape orientation
Videos for the Apple TV are to be submitted in 1920 x 1080 resolution. You can find detailed technical specifications and step-by-step instructions on how to submit app previews in the iTunes Connect Developer Guide.