this is a common question.
Meta and Apple Vision Pro don’t allow users to access raw camera buffer thus you can’t access passthrough view programmatically. I wrote details in here.
For your case, Quest handles passthrough view at low level and because softwares doesn’t have access to camera buffer, you can’t see that view in your screenshots.
I didn’t try yet but if you use Quest Link (Passthrough supports it) you can try to take actual screenshot from Windows.