Middleware to modify url

                services.AddHttpClient("cocApi", config =>
                {
                    config.BaseAddress = new Uri(hostBuilder.Configuration["Settings:BaseAddress"]);
                })
                .ConfigurePrimaryHttpMessageHandler(sp => new SocketsHttpHandler()
                {
                    MaxConnectionsPerServer = 10
                })
                .AddHttpMessageHandler((services) => new Foo());
            });
}

public class Foo : DelegatingHandler
{
    protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        Console.WriteLine("hi"); // this fires so i guess i got it right
        return base.SendAsync(request, cancellationToken);
    }
}