trying to apply kvantum theme to flatpak apps in nixos (I need help with qt)

context: QT: support Flatpak · Issue #916 · danth/stylix · GitHub
as you can see from logs the 33k one
kvantum is getting loaded but org.kde.desktop style is applied anyway
I don’t know how to fix and why is that happening
so yeah any help will be appreciated additional environment variables I can use anything
even additional apps I can use to demo and thanks