fix: proxy for authentication

nginx/templates/authentication.nginx

@@ -0,0 +1,10 @@
+server {
+        # Forward requests for the authentication server.
+        listen [::]:8000;
+        listen 8000;
+        server_name {domain};
+
+        location / {
+                proxy_pass              http://127.0.0.1:18000;
+        }
+}