'format' of code for CT video embeds widget

Hi, I've done a fair bit of searching and trying lots of different things, so I'm hoping I didn't miss an answer that was right under my nose. I'm trying to get the CT video embed widget set up (Rock Star theme) and not sure what to put in the code box. Tried lots of formats. Direct URL, share code, embed code I used on a different site for the same video. As in, https://www.youtube.com/watch?v=A7zX4hFNfxY http://youtube.com/embed/K3O37jNVh20?autoplay=1&rel=0 K3O37jNVh20 etc, etc, etc. None of these work. I'll I'm getting is the code showing on my web site. No player. It's at becomingjohnnynova.com BTW, whole thing is a big mess ATM, just trying to sort all this out. Haven't built a web site in 8 or 9 years, first time with a CMS first time WP, and first time with a template. So bit of a hurdle so far. Thanks for reading, David