Buttons w images

How do I get a button to show a custom image I need it for my world map in my game

Assign an image to the button state - hovered / unhovered and so on. Or insert an image into a button. Or do not do this with buttons in the first place as it is a bad idea. User borders / images as markers - more manageable in the long run.

create a hud class c ++ or from a blueprint. as you prefer. I leave a link for a tutorial. if you create a WidgetBlueprint it will be easier for you.