This plugin is created for WooCommerce, so you must have to WooCommerce is installed in your WordPress website. If your WordPress website haven’t WooCommerce installed then first install WooCommerce plugin. Please follow the link of WooCommerce plugin https://wordpress.org/plugins/woocommerce/. If you are new in WordPress and don’t know to how to install a WordPress plugin then follow the link https://codex.wordpress.org/Managing_Plugins.
You can find how to install WordPress plugin. For this plugin install you can also follow the same link.
WooCommerce Checkout Terms Conditions Popup maintain the standardization of woo themes. There are we are working on the slandered hooks and filter for the given functionality