Not trying to be a menace, but I just tried it out using xdg-portal-test-kde and the screenshot portal definitely works on KDE Plasma 5.27.10.
If you are experiencing issues with that, please create a bug report for xdg-desktop-portal-kde so it can be fixed.
What prevents you from using org.freedesktop.portal.Screenshot with GNOME and KDE as well? They both support taking screenshots using that method.
Unfortunately, you on GNOME and KDE you don’t have
org.freedesktop.portal.Screenshotmethod in/org/freedesktop/portal/desktop.Not trying to be a menace, but I just tried it out using xdg-portal-test-kde and the screenshot portal definitely works on KDE Plasma 5.27.10. If you are experiencing issues with that, please create a bug report for xdg-desktop-portal-kde so it can be fixed.
Strange, doesn’t work for me, I also run 5.27.10. Will take a look, thanks!