Scene Capture 2D transparent background

I’m struggling to achieve this, searshing everywhere for help, but still nothing, please help me, I’ll show my set-up trying to do this if one of you have some time, please help :"(

Is the render target on first image correct? The area at bottom left are sort of “reflecting” is ta ok? that area is really transparent?

In game the “transparent” area are shown “blank” above the rest of the map.