Whats wrong with my blueprint?

So i’m trying to make a racing AI at the moment with the help of waypoints. I set a navvolume already so they can move inside of it. I keep getting this warning that has to do with my cast and i dont know what im doing wrong, heres some pictures… Please help me!

Plugin your Stored Pawn Variable as input for the Cast.

I recommand you to watch this Training video. It goes over the basics everyone should know and Master =)