Imbed YouTube playlist in a page

Hello Folks at GP-Support !

I have forgotten how to do this. Or did YouTube make a change?

I have several video-playlists on my YouTube channel.
Each playlist is comprised of about eight video of two-to-three minutes in length.

I am having problems imbedding these playlists in WordPress pages on my site.
For some reason only the first video of the playlist is imbedded.

What am I doing wrong?

Thanks !

John