Dynamic Material Instance

I’ve been trying to implement this idea UE4 - Tutorial - Dynamic Materials in BluePrints! (Request!) - YouTube but with overlapping the trigger box and glass material which is initally opaque. But encountered this error This blueprint (self) is not a MaterialInstanceDynamic, therefore ’ Target ’ must have a connection. Here is my Event Graph

Hello, just use another Create Dynamic Material Instance node, which has no Primitive component node as input.

You have not connected the Create Material Instance block.

I have prepared a training video with subtitles about it.
I hope it helps someone.