Wordpress WooCommerce Plugin

I need a plugin to order "Free Samples" in WooCommerce. The "Free Sample" is a button like "Add to Cart" in Product details page, it will act same as "Add to Cart". Similar plugins are available, https://wordpress.org/plugins/woo-free-product-sample/
I need it in a customized way, you can check it here https://www.naturalstonetiles.com.au/, same function with attached design.

Thank you.