embeddable-dll-service - c++ - tunnel_proc_t

[Fabrizio Carimati]

I'm trying to embed tunnel.dll in a C++ Windows project,

LoadLibrary and GetProcAddress ok, but when i call the proc,
simply return 0 and i don't understand why.

The docs here:
https://git.zx2c4.com/wireguard-windows/about/embeddable-dll-service/README.md

what is the exact c++ definition of tunnel_proc_t ?

why the docs talk about a go_string (ascii?) when the C# example use a
LPWStr?

Thanks for any feedback.
Fabrizio Carimati