This guide really only provides an overview of what GraphQL is so I think it's fair they don't go in depth about auth topics.
If you're curios how authorization can be implemented in a GraphQL server, I recommend the following tutorial: https://www.prismagraphql.com/docs/tutorials/graphql-server-...
Also check out these two awesome projects that provide ways for implementing authorization with GraphQL:
- https://github.com/a-type/prisma-authorized
- https://github.com/maticzav/graphql-shield
If you want to see a practical example of how authorization can be implemented, check out this example project: https://github.com/graphcool/prisma/tree/master/examples/per...