How do I enable video in Scratch Live?

Video-SL is a separate add-on program which runs alongside Scratch Live. To authorize Video-SL, go into the setup screen in Scratch Live. Select the plug-ins tab and click the box to enable Video-SL. You will need to enter the serial number found inside the Video-SL box or the one which was sent to you when purchasing via Serato's online store.

With this complete Video-SL should now be available from the main screen of Scratch Live.