Thanks for reaching out. To add a YouTube video you will want to follow the steps below:
1) Create a Slide by selecting a Template through your Mango Signs dashboard end Editing it.
2) When your slide opens, you can find various apps on the left hand side of your screen. In the app list scroll down to find the YouTube app.
3) Paste the URL of the YouTube video in the App settings screen after you clicked on the YouTube app.
4) The YouTube app should now be added to your slide and you can now save your slide to send it out to your sign.
Mango Support Team