title: Use Postman to test a service with GraphQL in AWS (AppSync, Apollo)
body: <p>I'm trying to call a service through Graphql with Postman. From my app (React) I can use all the services with no problem (so, they are running ok), but I want to test them alone with Postman.</p>
  
  <p>I'm using AppSync, this is my configuration:</p>
  
  <pre><code>const AppSyncConfig = {
    url: environments.configAws.graphql.aws_appsync_graphqlEndpoint,
    region: environments.configAws.graphql.aws_appsync_region,
    auth: {
      type: AUTH_TYPE.API_KEY,
      apiKey: environments.configAws.graphql.aws_appsync_apiKey,
    }
  };
  </code></pre>
  
  <p>The environments vars are this:</p>
  
  <pre><code>graphql: {
      aws_project_region: "us-east-1",
  
      aws_appsync_graphqlEndpoint: "https://XXXXXXXXXXXXX.appsync-api.us-east-1.amazonaws.com/graphql",
      aws_appsync_region: "us-east-1",
      aws_appsync_authenticationType: "API_KEY",
      aws_appsync_apiKey: "da2-XXXXXXXXXXXX"
  }
  </code></pre>
  
  <p>And the app use this to make a query:</p>
  
  <pre><code>const client = new AWSAppSyncClient(AppSyncConfig, {
    link: createAppSyncLink({ ...AppSyncConfig,
      resultsFetcherLink: ApolloLink.from([
        setContext((request, previousContext) =&gt; ({
          headers: { ...previousContext.headers,
            Authorization: localStorage.getItem('token') ? localStorage.getItem('token') : ''
          }
        })),
        createHttpLink({
          uri: AppSyncConfig.url
        })
      ])
    })
  });
  
  const data_configs = client.readQuery({ query: query_configs });
  </code></pre>
  
  <p>In Postman I have this config, but I'm getting an error:</p>
  
  <p><a href="https://i.stack.imgur.com/eGnzS.png" rel="noreferrer"><img src="https://i.stack.imgur.com/eGnzS.png" alt="enter image description here"></a></p>
  
  <p>I took this code today, I haven't work before with Graphql (so neither with AppSync, ApolloLink, etc), but I ask in case it has a simple solution, or at least a hint for what should I check. Thanks.</p>