Install and Configure Nginx as an LBR task failed

hi everyone.
level 4 linux administration
in this task Install and Configure Nginx as an LBR i configured the /etc/nginx/nginx.conf
adding this
upstream app_servers {


and i got the welcome page nginx from the static page
and in every app server i changes the listening port to 80
vi /etc/httpd/conf/httpd.conf
and restarted the httpd service
curl http://localhost:80
the response is welcometo nautlius …
but bu finishing the lab i got
nginx isnt configured in all app servers
plz help

The web servers are not normally running on port 80. The task asks you to make changes to the load balancer not to make any changes to the app servers.