To embed a YouTube video in an HTML page, you can use the iframe element and the YouTube video URL.
Example:
<iframe width="560" height="315" src="https://www.youtube.com/embed/VIDEO_ID" frameborder="0" allowfullscreen></iframe>
Replace VIDEO_ID with the actual video ID of the YouTube video you want to embed. You can find the video ID in the YouTube video URL, which is the series of characters after the v= parameter.
You can customize the width and height of the video by changing the width and height attributes in the iframe element.
Note that the allowfullscreen attribute is required to allow the user to view the video in full screen mode.