export function getLiveKitURL(region: string | null): string {
  let targetKey = 'LIVEKIT_URL';
  if (region) {
    targetKey = `LIVEKIT_URL_${region}`.toUpperCase();
  }
  const url = process.env[targetKey];
  if (!url) {
    throw new Error(`${targetKey} is not defined`);
  }
  return url;
}