Embedding a YouTube playlist or channel gallery and (smart) YouTube livestream generally requires a YouTube API key. The default quota given by Google/YouTube, however, might not be enough for some applications. As of this writing (March 2020), the quota is 10000 requests per day. If you have a high traffic site, that limit might be too small. If so, we suggest that you try things like reducing your gallery's page size or using the plugin's caching feature. After that, your traffic might be so high that you still get the "Youtube Data API quota exceeded" error message. For that, you'll need to request that Google/YouTube give you a higher daily limit.
Here are the simple steps:
If you're interested in other optimizations outside what the API key uses, you should try activating the lazy loading feature, and turning on the (load-on-click) popup player for galleries to speed up page load.