diff --git a/nginx/nginx.conf b/nginx/nginx.conf
index 70733a0..703ffa5 100644
--- a/nginx/nginx.conf
+++ b/nginx/nginx.conf
@@ -1,10 +1,11 @@
-upstream backend {
-    server 100.66.170.15:8080;
-    server 127.0.0.1:8080;
-    server 172.18.10.8:8080;
-}
+# upstream backend {
+#     server 100.66.170.15:8080;
+#     server 127.0.0.1:8080;
+#     server 172.18.10.8:8080;
+# }
 server {
     listen 80;
+    set $backend_server 172.18.10.8:8080;
    
     root /usr/share/nginx/html;
     # Default file to serve for directory requests
@@ -25,7 +26,7 @@ server {
     }
 
     location /api/ {
-        proxy_pass http://100.66.170.15:8080;
+        proxy_pass http://$backend_server;
 
         # Cho phép upload file lớn (vd: 200MB)
         client_max_body_size 200M;
@@ -38,17 +39,17 @@ server {
         proxy_connect_timeout 300s;
         proxy_send_timeout 300s;
 
-        # CORS headers
-        add_header 'Access-Control-Allow-Origin' '*' always;
-        add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
-        add_header 'Access-Control-Allow-Headers' 'Content-Type, Authorization' always;
+        # CORS headers - Comment vi da xu ly o backend C#
+        # add_header 'Access-Control-Allow-Origin' '*' always;
+        # add_header 'Access-Control-Allow-Methods' 'GET, POST, OPTIONS' always;
+        # add_header 'Access-Control-Allow-Headers' 'Content-Type, Authorization' always;
 
         if ($request_method = OPTIONS) {
             return 204;
         }
     }
     location /api/Sse/events {
-        proxy_pass http://backend/api/Sse/events;
+        proxy_pass http://$backend_server/api/Sse/events;
         proxy_http_version 1.1;
 
         # cần thiết cho SSE