Hello
I need to lock the layout switching fot blender and krita applications
How to do it?

Keyboard switching is not done via kglobalaccel (like all other global shortcuts) so the kwin rule won't be effective.
If there's a dbus interface to toggle it, you may file a bug against kwin to conditionally call that as well (or by second rule) - otherwise you'll need such feature by kxkb first.

The system somehow seems to allow to only apply to the current window or application, but that likely won't help you?