Siri can control HomeKit accessories if they are configured using the Home app. Accessories can be identified by Siri using their name, location, or function. In addition, if you’ve configured a HomePod or an Apple TV as the switch, you can use Siri to control your equipment when outside your home.
Simply say “Show me the garden camera” to check the camera on your iPhone, iPad, or even your Apple Watch, or "Switch on the garden light"
To find out more, please read the official help provided by Apply to control your home with Siri.