ok, so seem to have fixed it. Notice a clue on the front page of the project in comment
It will be nice if you specify on top in documentation all the Nuget packages needed for this library.on adding a nuget package for newtonsoft and .net.http it worked (I assume the newtonsoft wasn't the issue)
https://www.nuget.org/packages/Newtonsoft.Json/
https://www.nuget.org/packages/Microsoft.Bcl.Async/
https://www.nuget.org/packages/Microsoft.Net.Http