I am using WordPress plugin for PushAssist, Which script do i need to add?

If you are using PushAssist WordPress plugin, you don't have to add any JS code within your site since the plugin installs it automatically.

If you run or own a WordPress based site you can simply install the PushAssist WordPress plugin from WordPress.org which will handle everything for you. It works well for all WordPress installations i.e. WooCommerce, Cart66, Wp-eCommerce, BBPress or any paid or free plugins available for WordPress.

Primarily, you should have

wp_footer();

hook placed in your footer file for the plugin to install the JS script to work.