Google Apps Script to post a message to Slack when someone responds to a Google Form.

slack-hook.gs

/**
 * ABOUT
 * Google Apps Script to post a message to Slack when someone responds to a Google Form.
 * 
 * Uses Slack incoming webhooks - https://api.slack.com/incoming-webhooks
 * and FormsResponse - https://developers.google.com/apps-script/reference/forms/form-response
 * 
 * 
 * AUTHOR
 * Akash A <github.com/akash1810>
 * 
 * 
 * USAGE
 * Free to use.
 */

// Create an incoming webhook here - https://api.slack.com/incoming-webhooks
var POST_URL = "https://hooks.slack.com/services/XXXX/XXXX/XXXX";

function onSubmit(e) {
  var response = e.response.getItemResponses();
  
  var fields = [
    {"title": "From", "value": e.response.getRespondentEmail()},
    {"title": "When", "value": e.response.getTimestamp()}
  ];
  
  for (var i = 0; i < response.length; i++) {
    var question = response[i].getItem().getTitle();
    var answer = response[i].getResponse();
    
    fields.push({"title": question, "value": answer});
  }
    
  var summaryAttachment = {
    "fallback": FormApp.getActiveForm().getTitle(),
    "pretext": "<!channel> New response submitted to: " + FormApp.getActiveForm().getTitle(),
    "title": FormApp.getActiveForm().getTitle() + " (responses)",
    "title_link": "https://docs.google.com/spreadsheets/d/" + FormApp.getActiveForm().getDestinationId(),
    "fields": fields,
    "color": "#393939"
  };
  
  var responseAttachment = {
    "fallback": FormApp.getActiveForm().getTitle(),
    "title": "Respond via email? (mailto link)",
    "title_link": "mailto:" + e.response.getRespondentEmail() + "?Subject=" + encodeURI(FormApp.getActiveForm().getTitle())
  };

  var options = {
    "method" : "post",
    "payload": JSON.stringify({
      "username": "Feedback",
      "icon_emoji": ":speech_balloon:",
      "attachments": [summaryAttachment, responseAttachment]
    })
  };

   UrlFetchApp.fetch(POST_URL, options);
};

I have questions, my forms is using checkbox, it seems the answer is not posted on slack, can you help me? @akash1810 ?