Cast to "Object"

Hi, I am trying to cast from a actor that has Activated “On Component Hit” But I don’t know what to put into the “Object” tab, the plan is when the object is hit it tells my widget to add to the score (Widget).

After you create a widget and add it to your viewport, you should assign it to a widget variable for future reference. I usually use a blueprint to create and store all reference to all the widget for ease on management, typical it is either your custom player controller blueprint, or your HUD blueprint.
So in more detail, assign your score widget to a 3DWidget, whenever you need to update your score, reference to that variable.

There should be more detail about how you should handle UMG inside these Unreal tutorial: A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums