Embedding Julia in c# ......about jl_value_t

New to Julia
1

I try Embedding Julia in c#,At the time of type conversion
I don’t know how to define jl_value_t, like this:
[DllImport(“libjulia.dll”, CallingConvention = CallingConvention.Cdecl)]
public static extern Type jl_value_t* ;

But this is wrong. What is the correct way to write? Thank you.