CIMRestService::getAccessToken

static function getAccessToken($appId, $userId)
{
	$session = BitrixRestEventSession::get();
	if(!$session)
	{
		return Array();
	}
	$auth = BitrixRestEventSender::getAuth(
		$appId,
		$userId,
		array('EVENT_SESSION' => $session),
		[
			'sendRefreshToken' => 1,
			'sendAuth' => 1
		]
	);
	return $auth? $auth: Array();
}