The "Xdp.Portal.take_screenshot" function is broken on KDE. Can't take a single screenshot somehow, this may not be your fault though.
Further information
https://imgur.com/a/ooXIFKh
Since I don't think it's actually your app failing, there are no relevant logs:
com.github.rajsolai.textsnatcher Gtk-Message: 18:24:22.170: Failed to load module "canberra-gtk-module" Process Done
Except it saying it's done its duty and called the actual screenshot tool.
I am closing the issue as the version 2.0.0 does not depend on portals for screenshot in X11 Systems. Thanks for trying out the application and giving feedback :)
System information
Graphics Processor: AMD Radeon RX 6900 XT
Application
Problem
Further information