With live video in Keynote, you can add a live stream of yourself, a device screen, or anything that can appear on camera to your presentation.

To learn more about this topic, visit the following articles:
Add live video in Keynote on Mac: https://apple.co/3EIZLUc
Use Keynote to present remotely in a video conference: https://apple.co/3mjjDH2

Additional Resources:

Get Support for Mac: http://apple.co/Mac

To subscribe to this channel: https://www.youtube.com/c/AppleSupport

To download the Apple Support app: http://apple.co/2hFtzIv

Apple Support on Twitter: https://twitter.com/AppleSupport

For more videos, go to Youtube Apple Channel