I am wanting to deploy a Django webapp with a PostgreSQL database to AWS Elastic Beanstalk using this tutorial, but I am so confused about pricing. It says it uses services in the AWS Free Tier, but those seem to be limited to a certain number of hours a month, so how do I make sure I don't go above that threshold? And how do I make sure I'm only using free services? They even require a card on file, so it seems really hard to make sure I don't get charged.