update README.md (#6190)

examples/ingress-resources/session-persistence/README.md

@@ -1,7 +1,7 @@
 # Session Persistence
 
 It is often required that the requests from a client are always passed to the same backend container. You can enable
-such behavior with [Session Persistence](https://www.nginx.com/products/session-persistence/), available in the NGINX
+such behavior with [Session Persistence](https://docs.nginx.com/nginx/admin-guide/load-balancer/http-load-balancer/#enabling-session-persistence), available in the NGINX
 Plus Ingress Controller.
 
 NGINX Plus supports *the sticky cookie* method. With this method, NGINX Plus adds a session cookie to the first response