Streamlining SlidesYearbook with Code

function makeCertificate() {

//the first question is always which app am I using?
var form = FormApp.getActiveForm();
var responses = form.getResponses();

//how many are there? Length gets that information
var len = responses.length

var last = len-1;
var response = responses[last];

//we need the users email address

var email = response.getRespondentEmail();

//get the questions

var items = response.getItemResponses();

//use logger to determine the number for each question.
//When I ran logger for 0, I learned that 0 = name
//I changed 0 to 1 and found that 1 = activity and so on.

Logger.log(items[0].getResponse());
var name = items[0].getResponse();
var activity = items[1].getResponse();
var hours = items[2].getResponse();

//Drive app may be turned off by school districts
//'1rH7UgQCFkjiPYxjxV24fE5tRYct13zEWpqY6D6Vt5Ac' is the doc ID for the template.
//Change the ID to match your template.

var file = DriveApp.getFileById('1rH7UgQCFkjiPYxjxV24fE5tRYct13zEWpqY6D6Vt5Ac');

//Make a copy of the template and share it with the user.
//Sharing the copy of the doc or slide is important because not all students have emails
//For the students who do have emails, we are getting the URL to email it

var copy = file.makeCopy('Certificate for '+name+ ' for '+activity);
var docID = copy.getId();
var certificate = DocumentApp.openById(docID).addViewer(email);
var docUrl = certificate.getUrl();

//Now for the magic - replacing the text

var body = certificate.getBody();
body.replaceText('<<name>>', name);
body.replaceText('<<activity>>', activity);
body.replaceText('<<hours>>', hours);

//Some users will have emails

GmailApp.sendEmail(email, 'Your certificate for '+activity, name+'\nHere is your certificate\n'+docUrl);

}