This is the embed code I got from Facebook
<iframe src="https://www.facebook.com/plugins/post.php?href=https%3A%2F%2Fwww.facebook.com%2Fbrendan.domotor%2Fposts%2F10158014151756039&show_text=true&width=500" width="500" height="703" style="border:none;overflow:hidden" scrolling="no" frameborder="0" allowfullscreen="true" allow="autoplay; clipboard-write; encrypted-media; picture-in-picture; web-share"></iframe>
However, if I change the height inside the iframe tag to something smaller than 703, say set it to 300. The page inside the content isn't scrollable, even I changed the scrolling to yes
<iframe src="https://www.facebook.com/plugins/post.php?href=https%3A%2F%2Fwww.facebook.com%2Fbrendan.domotor%2Fposts%2F10158014151756039&show_text=true&width=500" width="500" height="300" style="border:none;overflow:hidden" scrolling="yes" frameborder="0" allowfullscreen="true" allow="autoplay; clipboard-write; encrypted-media; picture-in-picture; web-share"></iframe>
Check the Facebook page source, the overflow is set to hidden for the plugin class.

If I unset the overflow, the page can be scroll. But since it's an iframe embed, what can I do to unset the css in the child page which is hosted inside iframe? Thanks!