How to create a reference to the MWArray API

Hello,

I am following this page https://www.mathworks.com/help/compiler_sdk/dotnet/integrate-your-net-assembly-into-a-c-application.html and when I try to find the MWArray API I can't. I find the file on my computer, but when I try to add it on visual studio 2017 it doesn't appear in the directory. I hope you can help me.