How to make a Enemy HP bar in world space in runtime and make it always face to camera?

I have create an HP progress bar for enemy and want to display it when player make damage on enemy.

I looked a lot of tutorials about HP bar but none has tell me how to create HP bar in runtime and make it in the world space so it can be occulde by other object.

I also has tried to add a widget component into enemy bp, however the color seems affected by the lighting and looks some kind weird to me.

If someone can tell me how to use blue print to create and add world-spaced HP widget just on top of my enemy character while it can keep on origial color?