saving screenshots to ~/Pictures without a dialogue window using gnome-screenshot in Mint 22

I'm running a fresh install of Mint 22. When I take a screenshot (via keyboard shortcut), a dialog appears to ask what I want to do with it (copy to clipboard, save to file, which file name...). I prefer the Ubuntu behaviour: just save the image to ~/Pictures directly in a timestamped file, no questions asked. I've tried setting /org/gnome/gnome-screenshot/auto-save-directory to /home/me/Pictures/ using dconf (as suggested in a few places on-line) but it has no effect. I've noticed that while the gnome-screenshot dialogue is open that gnome-screenshot was started with the --window switch. Is that hard-coded somewhere or can it be changed, e.g., to add -f somefilename.png? How do I configure gnome-screenshot to skip the dialogue and save the image to a file directly?