Return a result from node.js google drive api

I have a flow for uploading files to google drive using google drive API on a node.js server. Everything works, the file is uploaded to a specific folder inside my google drive. I created a file google-drive.js with all the function

const fs = require('fs');
const readline = require('readline');
const {google} = require('googleapis');

// 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';


function readFile(filePath) {
  fs.readFile('./server/drive/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.
    // return authorize(JSON.parse(content), listFiles);
     authorize(JSON.parse(content), filePath, uploadFile);
  })
}

/**
 * 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, filePath, 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));
    callback(oAuth2Client, filePath);
  });
}

/**
 * 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: 'offline',
    scope: SCOPES,
  });
  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, filePath);
    });
  });
}

/**
 * Lists the names and IDs of up to 10 files.
 * @param {google.auth.OAuth2} auth An authorized OAuth2 client.
 */
function listFiles(auth) {
  const drive = google.drive({version: 'v3', auth});
  drive.files.list({
    pageSize: 10,
    fields: 'nextPageToken, files(id, name)',
  }, (err, res) => {
    if (err) return console.log('The API returned an error: ' + err);
    const files = res.data.files;
    if (files.length) {
      console.log('Files:');
      files.map((file) => {
        console.log(`${file.name} (${file.id})`);
      });
    } else {
      console.log('No files found.');
    }
  });
}

function uploadFile(auth, filePath) {
  const drive = google.drive({version: 'v3', auth});
  const folderMetaData = {
    'name': 'TEST_FOLDER',
    'mimeType': 'application/vnd.google-apps.folder'
  };
  return drive.files.create({
    resource: folderMetaData,
    fields: 'id'
  }, function (err, file) {
    if (err) {
      console.log(err);
      return err;
    } else {
      const folderId = file.data.id;
      const fileMetadata = {
        'name': 'TEST_IMAGE',
        parents: [folderId]
      };
      const media = {
        mimeType: 'image/jpeg',
        body: fs.createReadStream(filePath)
      };
      drive.files.create({
        resource: fileMetadata,
        media: media,
        fields: 'id'
      }, (err, file) => {
        if (err) {
          // Handle error
          return err;
        } else {
          return file;
        }
      });
    }
  })

}

module.exports = {
  // Load client secrets from a local file.
  read: function (filePath) {
    return readFile(filePath);
  }
};

and in my server.js (main file) i have imported the google-drive.js and added a route like this :

app.post('/api/drive/auth', async (req, res) => {
  let result = null;
  result = await drive.read(req.body.filePath);
  console.log(result)
  res.status(200).json('success');
});

the problem is, i can't seem to get a result from the flow of the uploading, everytime i console.log(result) i get undefined.