GDEXTENSION export var with Node3D type

Hello, I have problems exporting a variable with a Node3D type to the engine.
I'm just learning C++ for godot and in the C++ guide there is a section with exporting variables

I'm trying to export Node3D so it looks something like this

but when I try to do this in C++, I get a lot of errors

godot-cpp\include\godot_cpp/core/method_bind.hpp(502): note: compiling a reference to an instance of the function template class "godot::MethodBindTR<T,R>"
with
[
T=godot::CameraFollower,
R=godot::Node3D
]
godot-cpp\include\godot_cpp/core/method_bind.hpp(468): note: during compilation of member function class template "GDExtensionClassMethodArgumentMetadata godot::MethodBindTR<T,R>::get_argument_metadata(int) const"
with
[
T=godot::CameraFollower,
R=godot::Node3D
]
godot-cpp\include\godot_cpp/core/method_bind.hpp(472): error C2065: METADATA: undeclared identifier
scons: *** [src\camera_follower.windows.template_debug.x86_64.obj] Error 2
scons: building terminated because of errors.

my code: