How to install hook procedure that monitors keystroke messages (WH_KEYBOARD_DLL or WH_KEYBOARD) using Easyhook C++

Question

I'm using Easyhook to hook keystrokes, but I don't understand how Easyhook works. How to install a hook to hook KeyboardProc (callback function). This is API of the LhInstallHook:

static void LhInstallHook(
    IntPtr InEntryPoint, 
    IntPtr InHookProc, 
    IntPtr InCallback, 
    IntPtr OutHandle
)