Why is my Google API access key not working?

Question

I am trying to access my google drive Files through the API. I'm using the google drive API code that was given to me in the Node.js quickstart, and altered it to suit my needs. I need the access token to be able activate this listFiles() function, using the auth argument given to it by the authorize() function. I'll paste the whole logic here so you can see.

These are some of the errors I'm getting:

(node:6844) UnhandledPromiseRejectionWarning: Error: invalid_request at Gaxios. at Generator.next () (node:6844) UnhandledPromiseRejectionWarning: Unhandled promise rejection. This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). (rejection id: 1)

Here's the code. I want to console.log the driveFiles in the listFiles() function, and I have a token.json to read from. I don't know what the problem is.

index.js:

const fs = require('fs');
const readline = require('readline');
const {google} = require('googleapis');
const { file } = require('googleapis/build/src/apis/file');

// If modifying these scopes, delete token.json.
const SCOPES = ['https://www.googleapis.com/auth/drive'];
// The file token.json stores the user's access and refresh tokens, and is
// created automatically when the authorization flow completes for the first
// time.
const TOKEN_PATH = 'token.json';

// Load client secrets from a local file.
fs.readFile('credentials.json', (err, content) => {
  if (err) return console.log('Error loading client secret file:', err);
  // Authorize a client with credentials, then call the Google Drive API.
  authorize(JSON.parse(content), listFiles());
});

/**
 * Create an OAuth2 client with the given credentials, and then execute the
 * given callback function.
 * @param {Object} credentials The authorization client credentials.
 * @param {function} callback The callback to call with the authorized client.
 */
function authorize(credentials, callback) {
  const {client_secret, client_id, redirect_uris} = credentials.web;
  const oAuth2Client = new google.auth.OAuth2(
      client_id, client_secret, redirect_uris[0]);

  // Check if we have previously stored a token.
  fs.readFile(TOKEN_PATH, (err, token) => {
    if (err) return getAccessToken(oAuth2Client, callback);
    oAuth2Client.setCredentials(JSON.parse(token));
    listFiles(oAuth2Client);
  });
}

/**
 * Get and store new token after prompting for user authorization, and then
 * execute the given callback with the authorized OAuth2 client.
 * @param {google.auth.OAuth2} oAuth2Client The OAuth2 client to get token for.
 * @param {getEventsCallback} callback The callback for the authorized client.
 */
function getAccessToken(oAuth2Client, callback) {
  const authUrl = oAuth2Client.generateAuthUrl({
    access_type: 'online',
    scope: SCOPES,
    response_type: 'token',
  });
  console.log('Authorize this app by visiting this url:', authUrl);
  const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
  });
  rl.question('Enter the code from that page here: ', (code) => {
    rl.close();
    oAuth2Client.getToken(code, (err, token) => {
      if (err) return console.error('Error retrieving access token', err);
      oAuth2Client.setCredentials(token);
      // Store the token to disk for later program executions
      fs.writeFile(TOKEN_PATH, JSON.stringify(token), (err) => {
        if (err) return console.error(err);
        console.log('Token stored to', TOKEN_PATH);
      });
      callback(oAuth2Client);
    });
  });
}



/**
 * Lists the names and IDs of up to 10 files.
 * @param {google.auth.OAuth2} auth An authorized OAuth2 client.
 */

async function listFiles(auth) {
  const drive = google.drive({ version: "v3", auth });
  const res = await drive.files.list({
    pageSize: 10,
    fields: "nextPageToken, files(id, name, description, mimeType, createdTime, parents, properties)",
  });
  const files = res.data.files;
  const fileArray = [];
  if (files.length) {
    const fileDisplay = [];
    const fileIdArray = [];
    const mimeType = [];
    const parents = [];
    const properties = [];
    console.log("Files:");
    for (var i = 0; i < files.length; i++) {
      fileDisplay.push(files[i].name);
      fileIdArray.push(files[i].id);
      mimeType.push(files[i].mimeType);
      properties.push(files[i].properties);
      parents.push(files[i].parents);
    }
    for (var y = 0; y < fileDisplay.length; y++) {
      fileArray.push({
        file: fileDisplay[y],
        id: fileIdArray[y],
        type: mimeType[y],
        parents: parents[y],
        properties: properties[y],
      });
    }
    app.set('fileArray', fileArray);
    console.log(fileArray)
  }
}

Token.json:

{"access_token":"***","scope":"https://www.googleapis.com/auth/drive","token_type":"Bearer","expiry_date":3599}

Really need some help. My client is getting upset.