Error with enqueuing CSS

In email-subscribers-advanced-form.php there’s an unnecessary slash that leads to breaking the link to styles.css:

wp_enqueue_style( 'email-subscribers-advanced-form', ES_AF_URL.'/includes/styles.css');

The slash before includes doubles it in the URL:

https://www.example.com/wp-content/plugins/email-subscribers-advanced-form//includes/styles.css

https://ww.wp.xz.cn/plugins/email-subscribers-advanced-form/