Taking screenshots under Wayland

Is there a way to take screenshots under Wayland from Snaps? I have a screenshot Application that implements image grabber for Gnome Wayland and Plasma Wayland, those relay on the specific DBus Interfaces and work outside Snaps. When running as Snap, none of the Wayland image grabber work, as far as I understand they wont work. I have tried now with a test call to DBus Interface org.freedesktop.portal.Screenshot but it doesn’t seem to work either, gives me only following error: The name org.freedesktop.portal.Screenshot was not provided by any .service files.

Am I missing something? Is this supported?

Anyone any idea if this is working or what the correct approach should be?

This is the output that I get when I try to take a screenshot via the same dbus that I use outside Snap: