Google Apps Script code to fetch pagespeed data and save to google sheet

Code.gs

var pageSpeedApiKey = 'PAGESPEED_API_KEY'; // use your api key here
var urlToMonitor = 'YOUR_WEBSITE'; //replace with website you want to monitor
var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
var sheet = spreadsheet.getSheetByName('results');

function createHeaders() {
   //Freezes the first row
  sheet.setFrozenRows(1);
  // Set the values we want for headers
   var values = [["Timestamp", "Device","Performance Score","LAB FCP", "LAB LCP", "LAB CLS", "LAB Interactive", "LAB Total Blocking Time", "LAB Speed Index"]];
  // Set the range of cells
  var range = sheet.getRange(1, 1, 1, 9);
  //Call the setValues method on range and pass in our values
  range.setValues(values);
}

function monitor() {
  var desktopInfo = getPageSpeedInfo('desktop');
  var mobileInfo = getPageSpeedInfo('mobile');
  instertDataToSheet(desktopInfo, 'desktop');
  instertDataToSheet(mobileInfo, 'mobile');    
}

function getPageSpeedInfo(strategy) {
  var pageSpeedUrl = 'https://www.googleapis.com/pagespeedonline/v5/runPagespeed?url=' + urlToMonitor + '&key=' + pageSpeedApiKey + '&strategy=' + strategy;
  var response = UrlFetchApp.fetch(pageSpeedUrl);
  var json = response.getContentText();
  return JSON.parse(json);
}

function instertDataToSheet(deviceInfo, deviceType){
  sheet.appendRow([
  // GMT+8:00 is for singapore 
  Utilities.formatDate(new Date(), "GMT+8:00", "yyyy-MM-dd'T'HH:mm:ss"),
  deviceType,
  deviceInfo.lighthouseResult.categories.performance.score * 100,
  deviceInfo.lighthouseResult.audits['first-contentful-paint'].numericValue,
  deviceInfo.lighthouseResult.audits['largest-contentful-paint'].numericValue,
  deviceInfo.lighthouseResult.audits['cumulative-layout-shift'].numericValue,
  deviceInfo.lighthouseResult.audits['interactive'].numericValue,
  deviceInfo.lighthouseResult.audits['total-blocking-time'].numericValue,
  deviceInfo.lighthouseResult.audits['speed-index'].numericValue,
 ]);  
}