Read RSS Feed in Google Apps Script and insert into active google sheet

Code.gs

function execute() {
    var url = "http://feeds.labnol.org/labnol"; //RSS Feed to parse
    main(url);
}
 
function main(url) {
 
  var ss = SpreadsheetApp.getActiveSheet();
 
  var property = PropertiesService.getDocumentProperties();
  var last_update = property.getProperty('last_update');
  last_update = last_update === null ? 0 : parseFloat(last_update);
  
  var feed = UrlFetchApp.fetch(url).getContentText();
  var items = getItems(feed);
  var i = items.length - 1;
  while (i > -1) {
    var item = items[i--];
    var date = new Date(item.getChildText('pubDate'));
    if (date.getTime() > last_update) {
      insertRow(item, sheet);
    }
  }
  property.setProperty('last_update', date.getTime());
}
 
function getItems(feed) {
  var doc = XmlService.parse(feed);
  var root = doc.getRootElement();
  var channel = root.getChild('channel');
  var items = channel.getChildren('item');
  return items;
}
 
function insertRow(item, sheet) {
  var title = item.getChildText('title');
  var url = item.getChildText('link');
  var author = item.getChildText('author');
  var date = new Date(item.getChildText('pubDate'));
  sheet.insertRowBefore(2);
  sheet.getRange('B2:E2').setValues([[title, url, author, date.toLocaleString()]]);
}