Deploy mode works only main page.

Hello guys, I’m new in Django. I’m taking cource in w3schools on Django.
I deployed my very first project on AWS Elastic Beanstalk. After deploying the project works only main page of the project. Other pages makes 504 error. On a local everything works well though, even connection to the AWS Postgre DB. Please advise what to make.
Here is the w3schools deploying page after which I stuck. All the other I made in accordance with it.

Thank you!