After Effects Auto Trace Animation

How did u search for all the liquid videos, bcz yours looked like its already matted/ alpha channeled, like black and white already, then only u apply auto trace. I could only find realistic video footage

I want to add the scribble effect to autotrace, but scriblle ignores the mask opacity so the mask just stays on screen. Pretty annoying and I don't know how to fix

why there is no auto trace to my ae?

Thank you