How to read ShapeIndex property via IEffect

I want to find out the shape to which the effect applies, Like PowerPoint.Effect.Shape in Microsoft office API.

I found the aspose cloud api has the ShapeIndex property that seems what I need:

https://docs.aspose.cloud/slides/working-with-animations-in-powerpoint-slides/
ShapeIndex int The index of the shape to which the effect applies.

But I can’t find this property in C#, IEffect interface, How can read this property in C#.
Thanks.

@tomnotcat

Actually, the animations on slides are defined on Slide.Timeline but you can still extract the effects that are applied on particular shape of the slide. I suggest you to please visit the following thread for your convenience.