Update nginx.conf to include KEYCLOAK_CLIENT_SECRET and add /redirect_uri location configuration

nginx.conf

@@ -1,5 +1,7 @@
 worker_processes 1;
 
+env KEYCLOAK_CLIENT_SECRET;
+
 events {
   worker_connections 1024;
 }
@@ -35,6 +37,10 @@ http {
       proxy_set_header X-Forwarded-Proto $scheme;
     }
 
+    location = /redirect_uri {
+      access_by_lua_file /usr/local/openresty/nginx/conf/auth.lua;
+    }
+
     # Protected root route (main site)
     location / {
       access_by_lua_file /usr/local/openresty/nginx/conf/auth.lua;