c++ signal to qml slot

I want to send a Signal from C++ to a Slot in my QML File. I already got it working without and primitive type parameters, although if I want to send a QString to my QML Slot I get an error whilst.

Thus, you can access the object that was loaded into the context of the QML engine, call its slot, and process the signal from this object.

Compares the two syntaxes for making signal-slot connections in C++. ... Qt offers two different ways to write signal-slot connections in C++: The string-based connection syntax and the functor-based connection syntax.