Get actor position inside a Render Target (UMG)

Hello there,

I wanted to make some kind of spawn UI in which (amongst other things) the player can see the Map from the front and click on a point where they want to spawn. These points are predetermined by actors.

And this is what I did:
I created a 2d Scene Capture Camera to render the scene to a render target to use it inside of UMG:

My problem:
I don’t know how to determine the location of the Spawn Point Actor in the Screenspace of this image widget. I tried setting the 2d scene capture as active player cam and play around with “Project world to screen”, but somehow I can’t get the right position out of that.

Does anyone have a clue what I can try to make this work? Thanks in advance.