If you have an Apple TV (3rd generation)*, you can control your HomeKit accessories in the Home app while you’re away from your home. To change user permissions, create automations, or stream HomeKit-enabled cameras remotely, you need an Apple TV (4th generation). If you add an Apple TV (4th generation) to a home that has an Apple TV (3rd generation) set up, the Apple TV (3rd generation) will stop being used for HomeKit remote access.