Use a feedback slide when you need to show information to the user in the flow of the quiz. You can also use skip logic so these slides are displayed only when specific previous answers have been selected, to achieve more personalized feedback.
In order to create a Feedback slide, select the Feedback type when creating a new slide:
In this case, just enter the text you need through the editor:
If you need to embed a video, for example a Youtube video, simply click on the Source code button
and paste the video code:
The result will be:
Sometimes it is useful to show a feedback slide only for a few seconds so the slide is presented and then auto-advances. In order to achieve this result, simply go to the General settings of the slide, check Auto-advance, and finally set the time in seconds:
You can also embed an animated GIF using HTML that when combined with the auto-advance feature, can be used as a typical spinner: