Auto Fill Google Doc.gs

function autoFillDoc(e) {
  //e.values is an array of last google form values when submit
  //see more at https://developers.google.com/apps-script/guides/triggers/events
  var timeStamp = e.values[0];
  var firstName = e.values[1];
  var lastName = e.values[2];
  var title = e.values[3];
  
  //file is the template file
  //see more at https://developers.google.com/apps-script/reference/drive/drive-app
  var file = DriveApp.getFileById('your_file_id_here');
  
  //make a copy of the template, name it, and optionally tell it what folder to live in
  //file.makeCopy will return a Google Drive file object
  //see more at https://developers.google.com/apps-script/reference/drive/file
  var folder = DriveApp.getFolderById('your_folder_id_here');
  var fileName = lastName + ',' + firstName;
  var newFile = file.makeCopy(fileName, folder);
  
  //the new file created, open it as a document by using its ID
  //see more at https://developers.google.com/apps-script/reference/document/document-app
  var newFileId = newFile.getId();
  var doc = DocumentApp.openById(newFileId);
  
  //change is in the body, we need to get that
  //see more at https://developers.google.com/apps-script/reference/document/document
  var body = doc.getBody(); 
  
  //call all of our replaceText methods
  //https://developers.google.com/apps-script/reference/document/body
  body.replaceText('{{First Name}}', firstName); 
  body.replaceText('{{Last Name}}', lastName);  
  body.replaceText('{{Title}}', title); 
  
  //save and close the document to persist our changes
  //see more at https://developers.google.com/apps-script/reference/document/document
  doc.saveAndClose(); 
}