gtkmm.h cannot open source file (Cross Compiling in Visual Studio for RaspberryPI)

Question

I am currently using Visual Studio 2019 in Windows to develop an application that should run on a Raspberry PI. I didn't have problems setting up other libraries (Like wiringPi or jsoncpp) but the same methods don't seem to work.

It gives different errors like "gtkmm.h cannot open source file" when I try to include <gtkmm.h>

What I tried so far:

• Adding gtkmm-3.0 (or gtkmm) in Library Dependencies for the linker
• Adding -lgtkmm-3.0 and -lgtkmm in Additional Options for the linker
• Adding pkg-config gtkmm-3.0 --cflags --libs in Additional Options
• Adding the following directory in Additional Include Directories: "/usr/include/gtkmm-3.0"

Has anyone ever cross compiled an application with this library and if so, what are the correct options I am missing?