In order for the plugin to function properly your theme footer.php must have this tag:

This tag is very important for the wordpress site. All themes must have it in their footer.php just before the closing tag or else it breaks many plugins.

In your wordpress admin panel go to Appearance -> Editor and click on footer.php in the list of files on the right.
Find tag and right before it copy and paste this:
<?php wp_footer(); ?>

Note: Backup your files before making this change. If you have any firewall plugins disable them before making changes.

If you would like to learn why it is important to have tag in your theme check function reference here.

Posted in: Common Support Questions