How to take a screenshot of a specified region in runtime?

Hi

I’m using HighResShot command in my blueprint project to take screenshots, and it works very well. But now i need to take screenshots of a specific region and not all the viewport, i know it’s possible to do that in the editor, but what i want is in runtime.

I found this :

and unfortunately… it doesn’t work !! I changed the last 3 digits by 0 to not enable mask, dumpbuffer or the captureHdr, but nothing! I mean the saved screenshot have the good specified resolution, but that’s it … it doesn’t capture the specified region at all, it always capture the entire screen and put it in that custom resolution, and it’s not what i want.

So, am i doing it right? or is there any other solution to do it ?

thanks