In the manual there's a section about introduction track.

https://centova.com/doc/cast/user_manual/01_usage_guide/02_advanced_usage/02_adding_an_introduction_track

I'd like to create a pre-roll, unfortunately, Maybe I'm missing something, but it seems impossible to find the correct way to do that. nothing in the manual looks like it is in the panel.
Can someone please help me??