How to access Facebook Analytics data using the marketing API? – Facebook api

I’m creating an app that needs to display Facebook marketing data such as insights, cpm, etc on various pages and posts associated with an account. I haven’t been able to figure it out so far. I’ve created an app, and have tried making calls from the sandbox account with the appropriate access token. When running the demo code to read the ad account’s name and age I am getting the following error. This has been really frustrating and my employer is getting mad. Any help is appreciated.

Code (node.js):

const adsSdk = require('facebook-nodejs-ads-sdk');
const accessToken = 'Sandbox acct token';
const api = adsSdk.FacebookAdsApi.init(accessToken);

const AdAccount = adsSdk.AdAccount;
const account = new AdAccount(XX Sandbox ID XX);
console.log(account.id)

account
  .read([AdAccount.Fields.name, AdAccount.Fields.age])
  .then((account) => {
    logPassedTest(test1 + ':Pass', account);
  })
  .catch((error) => {
   console.log(error);
  });

Error:

 message: 'Unsupported get request. Object with ID 'XXX' does not exist, cannot be loaded due to missing permissions, or does not support this operation. Please read the Graph API documentation at https://developers.facebook.com/docs/graph-api',

   { error:
      { message: 'Unsupported get request. Object with ID 'XXX' does not exist, cannot be loaded due to missing permissions, or does not support this operation. Please read the Graph API documentation at https://developers.facebook.com/docs/graph-api',
        type: 'GraphMethodException',
        code: 100,
        error_subcode: 33,
        fbtrace_id: 'ACp+q8Bas3Z' } },
  method: 'GET',
  url: 'https://graph.facebook.com/v2.11/X?fields=name%2Cage&access_token=XX',
  data: {} }