PublicKeyToken null #148

I included intercom client when I run the code for authentification
UsersClient usersClient = new UsersClient(new Authentication("token"));

i get this error when i start the project

System.TypeLoadException: 'Could not load type 'Intercom.Core.Authentication' from assembly 'intercom, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null'.'