Request to fetch AD token for the Immersive Reader using request

getTheToken.js

// Making a request to get the token with access to the .env file we created back in step 2

// One can wrap this into a route/endpoint for the frontend to query before starting the Immersive Reader resource
// router.get('/GetTokenAndSubdomain', function(req, res) {
  request.post({
      headers: { 'content-type': 'application/x-www-form-urlencoded' },
      url: `https://login.windows.net/${process.env.TENANT_ID}/oauth2/token`,
      form: {
        grant_type: 'client_credentials',
        client_id: process.env.CLIENT_ID,
        client_secret: process.env.CLIENT_SECRET,
        resource: 'https://cognitiveservices.azure.com/'
      }
    },
    function (err, res, tokenResult) {
      if (err) {
        console.log(err);
        return res.status(500).send('Cognitive Services token error, did not receive the token');
      }

      var tokenResultParsed = JSON.parse(tokenResult);

      if (tokenResultParsed.error) {
        console.log(tokenResult);
        return res.send({ error: "Unable to acquire Azure AD token. Please check if your .env values are correct." })
      }

      var token = tokenResultParsed.access_token;
      var subdomain = process.env.SUBDOMAIN;
      return res.send({ token, subdomain });
    });
// })