C#: How to Marshal VariantBool to managed boolean?

Question

I am currently working on a Wrapper Class for a C++ Library in C# (dotnet core 3.1 on debian linux) and struggling with DllImport the following method (taken from the libs documentation):

HRESULT __stdcall InitializeEngine(
    BSTR CustomerProjectID,
    BSTR LicensePath,
    BSTR LicensePassword,
    BSTR FREngineDataFolder,
    BSTR FREngineTempFolder,
    VARIANT_BOOL IsSharedCPUCoresMode,
    IEngine** Engine);

Update: Looking further in the header files, the COM Types are typedefs. Therefore the actual signature looks something like this:

int __stdcall InitializeEngine(
        wchar_t* CustomerProjectID,
        wchar_t* LicensePath,
        wchar_t* LicensePassword,
        wchar_t* FREngineDataFolder,
        wchar_t* FREngineTempFolder,
        short IsSharedCPUCoresMode,
        IEngine** Engine);

My Import currently looks like this:

[DllImport("FREngine", CallingConvention = CallingConvention.StdCall)]        
extern static int InitializeEngine(
        [MarshalAs(UnmanagedType.LPWStr)]string customerProjectID, 
        [MarshalAs(UnmanagedType.LPWStr)]string licensePath, 
        [MarshalAs(UnmanagedType.LPWStr)]string licensePassword, 
        [MarshalAs(UnmanagedType.LPWStr)]string frEngineDataFolder, 
        short isSharedCPUCoresMode,
        ref IntPtr engine);

But this does not work. Is this the correct translation of the method signature?