<script src="livesdk.umd.js"></script>
<script>
  const sdk = new LiveSDK.LiveSDK({
    activityId: '...',
    token: '...',
    merchantId: '...'
  });
  // 清晰度插件（opt-in）：设备分级起播 + 自动降档
  sdk.use(new LiveSDK.DefinitionPlugin({ defaultQuality: 'auto' }));
  sdk.mount('#live-container');
</script>