To externally get certain data about YouTube videos, the embedplus.com YouTube WordPress plugin needs access to the YouTube Data API v3. Access is managed by an Google/YouTube API key. Watch this video to learn how to create one. Certain sensitive pieces are blurred/cut out, but the steps are easy to follow regardless.
For more detailed instructions, read: https://www.embedplus.com/how-to-crea...
You can learn other tips for YouTube embedding in WordPress here: https://www.embedplus.com/youtube-plu...