Getting a virtual keyboard to work on KDE Plasma 6 / Plasma mobile

I want to use plasma mobile on my convertible NixOS machine so I can interact with it easier in tablet mode. However after 4 hours of struggling today, I have not been able to get a single virtual keyboard to even function.

I imported the two maliit packages in my confit, and even set some environment variables to hopefully get it to work. But it didn’t work after all. When I press on a text box, no virtual keyboard appears.
When I look into my kde settings, I can even see maliit as an option. But everything is greyed out and I can’t change anything.

Executing
maliit-server

Gives me an error:

org.maliit.framework: bool MIMPluginManagerPrivate::loadPlugin(const QDir&, const QString&) Error loading plugin from "/nix/store/4z5pk4rm5q0gf9m6imj3jhhnklcn96fi-maliit-framework-2.3.0/lib/maliit/plugins/libmaliit-keyboard-plugin.so" "The shared library was not found."
org.maliit.framework: No plugins were found. Stopping.