function runTask() {
  // Configuration
  var API_ENDPOINT = `<UNIQUE 2FA CONFIGURATION URL>`;
  // In this example, SUBJECT_MATCH has a static email subject, but 
  // it can also be a regular expression.
  var SUBJECT_MATCH = 'verification code'; 
  // In this example, INBOX_SEARCH_FILTER is a filter for unread
  // emails in the inbox that were received in the last hour with 
  // the defined subject.
  var INBOX_SEARCH_FILTER = `is:unread newer_than:1h in:inbox subject:(${SUBJECT_MATCH})`; 
  // In this example, OTP_REGEXP_MATCH has a regular expression with:
  //  * A first group for parsing to where the OTP starts.
  //  * A second group for parsing the OTP.
  //  * A third group for parsing the rest of the email body.
  var OTP_REGEXP_MATCH = '^(.* code is: )([0-9]{6})(.*)';
  
  var nrUnread = GmailApp.getInboxUnreadCount();
  Logger.log(`Unread messages: ${nrUnread}`);
  if (nrUnread === 0) {
    Logger.log('No unread messages');
    return;
  }
  var threads = GmailApp.search(INBOX_SEARCH_FILTER);
  if (threads.length === 0) {
    Logger.log('No threads matching the filter');
    return;
  }
  Logger.log(`Threads matching the filter: ${threads.length}`);
  var reIsOTP = new RegExp(SUBJECT_MATCH, 'i');
  var reExtractOTP = new RegExp(OTP_REGEXP_MATCH, 'im');
  for (var i = 0; i < threads.length; i++) {
    var subject = threads[i].getFirstMessageSubject();
    if (reIsOTP.test(subject)) {
      var messages = threads[i].getMessages();
      for (var j = 0; j < messages.length; j++) {
        if (messages[j].isUnread() === false) {
          continue;
        }
        var body = messages[j].getBody();
        Logger.log(body)
        var match = body.match(reExtractOTP);
        // The following two lines of code depend on the position 
        // of the OTP in the regular expression defined in 
        // OTP_REGEXP_MATCH. So, review this code if you change 
        // the position of the OTP in the regular expression.
        if (match && match.length > 2) { 
          const extractedOTP = match[2];
          Logger.log(`Extracted OTP: ${extractedOTP}`);
          var postOptions = {
            method: 'POST',
            headers: {
              'Content-Type': 'application/json',
            },
            payload: JSON.stringify({
              otp: extractedOTP,
            })
          };
          var response = UrlFetchApp.fetch(API_ENDPOINT, postOptions);
          Logger.log(`API Response :: ${response}`);
          messages[j].markRead(); // Set message as read
          return;
        }
      }
    }
  }
}

function extractOTPFunction() {
  runTask();
  Utilities.sleep(15 * 1000);
  runTask();
  Utilities.sleep(15 * 1000);
  runTask();
  Utilities.sleep(15 * 1000);
  runTask();
}