'Only an admin can share a calendar.']); exit; } $calendar_id = intval($_GET['id'] ?? 0); $calendar = calendarList()[$calendar_id] ?? null; if (!$calendar) { echo json_encode(['error' => 'That calendar no longer exists.']); exit; } $feed_key = (string) $calendar['calendar_feed_key']; $urls = $feed_key !== '' ? calendarFeedUrls($feed_key) : null; $csrf = $_SESSION['csrf_token']; ob_start(); ?>