Getting error while uploading image using tinymce

Hi, I am using TinyMCE. when i try to upload a image this error popup appears Cannot read properties of undefined (reading 'then')

this is my code

  <script>
    document.addEventListener('DOMContentLoaded', function () {
      tinymce.init({
        selector: '#body', // Target the textarea
        plugins: 'image link code table lists',
        toolbar: 'undo redo | bold italic | alignleft aligncenter alignright alignjustify | bullist numlist outdent indent | link image',
        height: 400,
        images_upload_url: 'admin/notification/upload',
        // Custom image upload handler
        images_upload_handler: function (blobInfo, success, failure) {
          let xhr, formData;
          xhr = new XMLHttpRequest();
          xhr.withCredentials = false;
          xhr.open('POST', '/admin/notification/upload');
          const token = '{{ csrf_token() }}';
          xhr.setRequestHeader("X-CSRF-Token", token);
          xhr.onload = function() {
            let json;
            if (xhr.status != 200) {
              failure('HTTP Error: ' + xhr.status);
              return;
            }
        
            success(xhr.responseURL);
          };
          formData = new FormData();
          formData.append('file', blobInfo.blob(), blobInfo.filename());
          xhr.send(formData);
        },
        /* enable title field in the Image dialog*/
        image_title: true,
        /* enable automatic uploads of images represented by blob or data URIs*/
        automatic_uploads: true,
        file_picker_types: 'image',
      
      });
    });
  </script>