Docker compose error - load balancer

Hi All, in. my progression to learn docker, i have reached docker-compose and now stuck with something unique. I tried create a docker load balancer using nginx. I am using this article but when i ran docker compose i got this error.

I know i am doing something wrong but not sure where to check. I have copy pasted the config same as the article. I guess i need to change the server IP and make it localhost in the nginx.conf file as everything is running locally on my mac.