How to trigger KWin's titlebar menu in GTk-based applications using CSD?

Right-clicking on a window’s titlebar opens a menu with among others a submenu allowing to send the window to another virtual desktop.

How does one trigger this menu in GTk applications that use their own client-side decoration?

For me the alt+F3 keyboard shortuct is best way to achieve this

Thanks, that does it indeed! I should have known there’d be a shortcut for that, it’s even under the same Fkey as I once used to trigger window resize/move operations.