How can I add purecounter.js to my WordPress site?

<div class="counter-number">
  <span data-purecounter-start="0"
        data-purecounter-end="6"
        data-purecounter-duration="1"
        class="purecounter"></span>
</div>

new PureCounter();

wp_register_script(
  'purecounter',
  get_template_directory_uri() . '/assets/vendor/purecounter/purecounter_vanilla.js',
  array('jquery'),
  '1.5.0',
  true
);
wp_enqueue_script('purecounter');

Uncaught ReferenceError: PureCounter is not defined

The counter number not showing. Getting this error.