I have a simple script that executes once form submit. It is a simple test script applied html for email.
function sendEmail(e) {
  
  //response
  //getRespondentEmail()
  var html = HtmlService.createTemplateFromFile("email.html");
  var htmlText = html.getCode();
  
  var emailTo = e.response.getRespondentEmail();
  var subject = "Thanks for participating";
  var textBody = "This email requries HTML support, please maek sure you open with a client taht support.";
  var options = { htmlBody: htmlText };
  
  
  if(emailTo !== undefined){
    GmailApp.sendEmail(emailTo,subject,textBody,options);
  //(recipient, subject, body, options)
  }
}
But it always noticed TypeError: Cannot read property 'response' of undefined.
TypeError: Cannot read property 'response' of undefined (line 8, file "Code")
either the respose from my host email said 'Failed to send email: no recipient'

I do not know why it does not work, but I see someone successfully applied through above google app script.
 
    