I don't think you can imbed a Youtube video but you can just put the URL or share the link in between

< center> youtube video link goes here < /center>

just delete the spaces after the < part of the code. You can just put the Youtube link but it may not center the image of the link. You can also click the chain looking thing for links in the editor here and you can just have blue text that when clicked links to the video.

Excellent shots! I really enjoyed this post Liz! Keep up the great work.