HTTPS in C# .net framework 4.7.2

Question

im trying to make backend in c# on my linux ubuntu server without using apache2 or ngnix. Everything worked fine, until i've tried to make https, i made a certificate and the key, using openssl copied it to /etc/ssl/certs and /etc/ssl/certs

and i wrote this using different stackoverflow questions:

            HttpListener listener = new HttpListener();
            string certificatePath = "whoisalmo.crt";
            if (!File.Exists(certificatePath))
            {
                Console.WriteLine($"Cannot find certificate file: {certificatePath}");
                return;
            }
            var certificate = new X509Certificate2(certificatePath);
            string path = System.IO.Path.GetDirectoryName(Assembly.GetEntryAssembly().Location);
            string[] prefixes = { "https://+:443/", "http://*/" };
            foreach (string s in prefixes)
                listener.Prefixes.Add(s);
            listener.Start();
            while(true) 
            {
            ...
            }

when i start this, the http works, but https doesnt, I wont get error in the app but when i try to access the website it says connection was reseted.

i tried

• Making new certificate
• rebooting after coping the crt and key..
• opening firewall on pc and portforwarding on router