App Script to get info from a tracker connected to this https://codepen.io/saamerm/pen/yLwYvXe

AppScript.js

function doGet(request){
  var result = processRequest(request);
  return ContentService
    .createTextOutput(result)
    .setMimeType(ContentService.MimeType.TEXT);
}

function processRequest(e)
{
  // Open Google Sheet using ID
  var sheet = SpreadsheetApp.openById("{REPLACE_ME}");
  var result = "data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHElEQVQI12P4//8/w38GIAXDIBKE0DHxgljNBAAO9TXL0Y4OHwAAAABJRU5ErkJggg==";
  try{
    // Get all Parameters
    var today = new Date();
    var date = today.getFullYear()+'-'+(today.getMonth()+1)+'-'+today.getDate();
    var time = today.getHours() + ":" + today.getMinutes() + ":" + today.getSeconds();
    var dateTime = date+' '+time;
    var info = "No extra info"
    if (e && e.queryString && e.queryString.length > 0 ){
      info = e.queryString
    }
    // Append data on Google Sheet
    var rowData = sheet.appendRow(["Email", "Opened", info, dateTime]);
  }catch(exc){
    var rowData = sheet.appendRow(["asd", "asd", "asd", "asd", "0"]);
    // If error occurs, throw exception
    result = {"Status": "FAILED", "Message": exc};
  }
  // Return result
  return result;
}

function test(){
  var Name = "Saamer"
  var Email = "asd@asd.com"
  var Message = "This is a web Message"
  var myJSObject='{"Name": "' + Name + '", "Email" : "' + Email + '", "Message" : "' + Message + '"}';
  var result = processResult(JSON.parse(myJSObject))
  console.log(result)
}

function testGet(){
  var e = { "queryString" : "src=Hel"}
  var result = processRequest(e)
  console.log(result)
}