Google Sheet Webhook Receiver. Recives JSON data posted on the webhook URL. Puts timestamp and JSON data in the Google Sheet.

webhook_code.gs

//this is a function that fires when the webapp receives a GET request
function doGet(e) {
  return HtmlService.createHtmlOutput("request received");
}

//this is a function that fires when the webapp receives a POST request
function doPost(e) {
  var params = JSON.stringify(e.postData.contents);
  params = JSON.parse(params);
  var myData = JSON.parse(e.postData.contents);
  var sheet = SpreadsheetApp.getActiveSheet();
  var lastRow = Math.max(sheet.getLastRow(),1);
  sheet.insertRowAfter(lastRow);
  var timeZone = Session.getScriptTimeZone();
  var timestamp = date = Utilities.formatDate(new Date(), timeZone, "MM-dd-yyyy | HH:mm:ss");
  sheet.getRange(lastRow + 1, 1).setValue(timestamp);
  sheet.getRange(lastRow + 1, 2).setValue(params);
  SpreadsheetApp.flush();
  return HtmlService.createHtmlOutput("post request received");
}