Dear Maintainer, The version of flameshot included in Bookworm is incapable of taking screenshots in Wayland. When you tell it to take a screenshot it just hangs. I cloned https://github.org/flameshot-org/flameshot, ran "apt build-dep flameshot", and then followed the instructions in README.md to build and install in /usr/local, and it works just fine. This is probably just a matter of upgrading the Debian repository to match the current Flameshot codebase.
This is more complicated than I thought. It turns out that the flameshot that gets launched on startup in Waldn if I have it configured to do that doesn't work, but if I close and relaunch flameshot from the terminal it is able to capture screenshots. So the problem seems to be that flameshot processes that aren't launched interactively don't work properly under Wayland. I've posted about this at https://github.com/flameshot-org/flameshot/issues/3326 .