Ubuntu WSL2 cannot find example files of GTK3

I am learning gtk3 from the documentation and it works fine until a code has example headers included in it like this:

#include "exampleapp.h"#include "exampleappwin.h"

When I compile like the documentation says:

gcc `pkg-config --cflags gtk+-3.0` -o gui4 example4.c `pkg-config --libs gtk+-3.0`

I get this error:

fatal error: exampleapp.h: No such file or directory

I have installed gtk examples using:

sudo apt-get install -y gtk-3-examples

Running Ubuntu on WSL2 on Windows. Editor is VSCode. Just using its editor and terminal.How do I fix this?