Is windows authentication supported by Microsoft.AspNetCore.Proxy?

I have a SharePoint 2013 Server "spserver" configured to use Windows Authentication and a ASP.NET Core App that uses Microsoft.AspNetCore.Proxy.

public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
    loggerFactory.AddConsole();

    app.UseStaticFiles();

    app.MapWhen( _ => true, builder => builder.RunProxy(new ProxyOptions
    {
        Scheme = "http",
        Host = "spserver",
        Port = "80"
    }));
}

I'm having problems with Windows Authentication. Some requests are authenticated successfully, but other ones don't authenticate, after entering the credentials on the browser dialog several times.

Is there a way to get Microsoft.AspNetCore.Proxy work with Windows Authenticated SharePoint Server?