Live Stream option is only available on new devices.
For the first use, you will need to connect your YouTube channel to the system. After this initial setup, the system will remember your channel for future streams.
Please note that YouTube requires a 24-hour activation period before your first live stream. This means you must request to start a live stream on your YouTube channel at least 24 hours in advance so that YouTube can verify your account.
Explanation of how to add your YouTube account in a video.