about google apps script inline images in gmail message body

Question

So I have a draft email looks like this :

and this is how my email looks after mailing it

I can find those images in email as attachment like this

and here is my script I am using so can anyone here tell me if I am doing something wrong and what is wrong in this code, because idk much about google app script, I just found this script from the stack I am not able to find that post again so couldn't upload its link.

  function main( ) {

  var thread = GmailApp.getDrafts()[0];
  var TemplateMessage = thread.getMessage();

  Logger.log(TemplateMessage.getSubject());

  var emailTemplate = TemplateMessage.getBody();
  var rawContent = TemplateMessage.getRawContent();
  var attachments = TemplateMessage.getAttachments();

  var regMessageId = new RegExp(TemplateMessage.getId(), "g");
  if (emailTemplate.match(regMessageId) != null) {
    var inlineImages = {};
    var nbrOfImg = emailTemplate.match(regMessageId).length;
    var imgVars = emailTemplate.match(/<img[^>]+>/g);
    var imgToReplace = [];
    if(imgVars != null){
      for (var i = 0; i < imgVars.length; i++) {
        if (imgVars[i].search(regMessageId) != -1) {
          var id = imgVars[i].match(/realattid=([^&]+)&/);
          if (id != null) {
            var temp = rawContent.split(id[1])[1];
            temp = temp.substr(temp.lastIndexOf('Content-Type'));
            var imgTitle = temp.match(/name="([^"]+)"/);
            if (imgTitle != null) imgToReplace.push([imgTitle[1], imgVars[i], id[1]]);
          }
        }
      }
    }
    for (var i = 0; i < imgToReplace.length; i++) {
      for (var j = 0; j < attachments.length; j++) {
        if(attachments[j].getName() == imgToReplace[i][0]) {
          inlineImages[imgToReplace[i][2]] = attachments[j].copyBlob();
          attachments.splice(j, 1);
          var newImg = imgToReplace[i][1].replace(/src="[^\"]+\"/, "src=\"cid:" + imgToReplace[i][2] + "\"");
          emailTemplate = emailTemplate.replace(imgToReplace[i][1], newImg);
        }
      }
    }
  }
  //////////////////////////////////////////////////////////////////////////////
  var message = {
    htmlBody: emailTemplate,
    subject: TemplateMessage.getSubject(),
    attachments: attachments,
    inlineImages: inlineImages
  }

  GmailApp.sendEmail(Session.getActiveUser().getEmail(), TemplateMessage.getSubject(), "", message);
}