How to share private video for a list of emails using YouTube Data API

I need to update an upcoming Broadcast with YouTube Data API. I'm following this guide https://developers.google.com/youtube/v3/live/docs/liveBroadcasts/update

Right now I can change all the snippet info with the PHP SDK, but I don't see anywhere how to add trough the API a list of emails who will have access to the private broadcast video (just how we can do trough the panel of YouTube):

My current PHP try is this:

$videoId = $mVideoLive->id;$liveBroadcast = new Google_Service_YouTube_LiveBroadcast();$liveBroadcast->setId($videoId);$liveBroadcastSnippet = new \Google_Service_YouTube_LiveBroadcastSnippet();$liveBroadcastSnippet->setTitle("Mi gran titulo");$liveBroadcastSnippet->setDescription("Hola este es mi descripcion genial");$datetime = new DateTime('2021-04-08 11:00:00');$startTime = $datetime->format(DateTime::ATOM); // Updated ISO8601$liveBroadcastSnippet->setScheduledStartTime($startTime);$liveBroadcast->setSnippet($liveBroadcastSnippet);$response = $service->liveBroadcasts->update("snippet", $liveBroadcast);

Any thoughts?