Qt app to take its own screenshot

I've been looking everywhere, and I apologize if this is the wrong channel to submit this question (which may become a request)

Weston by default has the keybind of super+s for screenshot and this works fine, although our use-case doesn't have a keyboard, this will be done by touching through a QT app running on Weston. We either had to make the Qt talk to Weston sending a keybinding (xdotool is not available clearly, and we'll try ydotool/dotool), but this is not the best approach IMO. I saw the possibility to use weston-screenshooter but this demand me to use --debug when running Weston which is not production safety. The closest request I found was this (#765)... I know nothing about portals,

Is there any better way for an app running on top of Weston to take a screenshot of its own or the whole screen? (the app is running as kiosk mode anyway)