How to make a 2D fog of war?

I am making a top down shooter and I wanna make a level with fog of war.

I want to have fog of war, but I don't want the entire map outside of player's field of view to be black until they move. I would like to have a fog of war like in Among us, where the entire map is visible, just darker, and all different players or enemies are hidden.

I looked everywhere and I couldn't find anything like that.