Working with AWS Amplify and Securing GraphQL API Calls

Question

const client = new AWSAppSyncClient({
  url: AWSConfig.aws_appsync_graphqlEndpoint,
  region: AWSConfig.aws_appsync_region,
  auth: {
    type: AWSConfig.aws_appsync_authenticationType,
    jwtToken: () => req.headers.authorization,
  },
  disableOffline: true,
  offlineConfig: {
    keyPrefix: "myPrefix",
  },
});

I have been able to secure my API calls on my server endpoint by configuring an AppSync client, but I was hoping to do the same but use the API client provided by AWSAmplify, wondering if it is even possible.

This is my original code with the API client, but I kept getting no user available error. Is there a configuration option I am missing that allows me to set the token?

const { data, errors } = await API.graphql(
  {
    query: listPlayers,
    authMode: "AMAZON_COGNITO_USER_POOLS",
  }
);