Hi Jose-Xu, no problem at all on the late reply! :)
It might help to break down the expected behavior. When you say you are trying to access localhost:3000/graphql, do you mean:
The only way to access the endpoint at localhost:3000/graphql is by sending a POST request (in this tutorial's case, through Insomnia) and have the requests body be formatted as a GraphQL Query. So, trying to access localhost:3000/graphql from a browser will always return an error because it's never expecting a GET request.
On the other hand, if your issue is that you're getting errors with sending a POST request with a GraphQL Query body, then the issue is probably with the request body itself! Are you using Insomnia (or something similar, like Postman) to send the POST request? And if so, can you send a screenshot so we can look over it? :)
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