WooCommerce (little project)

I have a small project for an eCommerce website built with Wordpress + Woocommerce. Unfortunately, online store does not show the "add to cart" button. There seems to be problems with the purchase process. The project requires a person who can troubleshoot with the "add to cart" button, making the process from adding to cart to completing payment effective and completed (need to check the correct implementation of Stripe payment processor, and test a couple of demo orders). Thank you.