Thanks for using Bitnami! Did you take a look at this guide https://docs.bitnami.com/aws/infrastructure/lamp/administration/create-custom-application-php/? because it's the first step to create a new application.
The next step will be the guide you posted.
After that could you make sure that your
serverName redirect to your instance IP?
if you already did all these steps, could you add more information about your issue?