Implementing OpenID in ASP5

I'm attempting to implement Steam OpenID integration into an ASP5/MVC6 site. The existing OpenID libraries do not work with ASP5 as they seem to rely on HttpContext, which doesn't exist.

This is the only compatible library that I can find:

 "Microsoft.AspNet.Authentication.OpenIdConnect": "1.0.0-beta4",

I've configured it in Startup.ConfigureServices like so:

    public void ConfigureServices(IServiceCollection services)
    {
        ..
        services.ConfigureOpenIdConnectAuthentication(options =>
        {
            options.Authority = "http://ift.tt/1glcWoz";
            options.ClientId = "[ClientIDHere]";
        });
    }

and in Startup.Configure:

app.UseOpenIdConnectAuthentication();

My real question is a simple one, how do I actually use this library in my application to create the OpenID requests? Documentation seems non-existent on this library (typical for a beta, of course) and examples are scarce.