secured admin frontend as well

admin/nginx.conf

@@ -9,6 +9,14 @@ server {
     try_files $uri $uri/ /index.html;
   }
 
+  location = /backend {
+    return 301 /backend/;
+  }
+
+  location /backend/ {
+    proxy_pass http://borrow_system-backend_v2:8004/;
+  }
+
   location ~* \.(?:js|mjs|css|png|jpg|jpeg|gif|ico|svg|woff2?)$ {
     expires 1y;
     access_log off;