Beginner material change on key press

hello.
sorry this is really amateur, but I looked everywhere on the forum and youtube and haven’t been able to solve this. I am just experimenting to see how to change materials with a keyboard press. I have tried creating an an actor blueprint class as well as attaching a blueprint to the static mesh. Neither are functioning.

I don’t think I should have to add any inputs to the static mesh component variable.

Here is an image.
Thanks