Sitefinity OWIN LetsEncrypt

Startup.cs

using LetsEncrypt.Owin;
using Owin;
using Telerik.Sitefinity.Owin;

namespace SitefinityWebApp
{
    public class Startup
    {
        public void Configuration(IAppBuilder app)
        {
            // Register default Sitefinity middlewares in the pipeline
            app.UseSitefinityMiddleware();
            app.UseStaticFiles();
            app.UseAcmeChallenge();
        }
    }
}