WooCommerce Official Shortcodes

https://docs.woocommerce.com/document/woocommerce-shortcodes/#section-19

Execute a PHP function in a form post

https://stackoverflow.com/questions/595358/how-can-i-execute-a-php-function-in-a-form-action

This explains how to add custom data to the cart. Maybe useful.

https://pluginrepublic.com/add-custom-cart-item-data-in-woocommerce/

This is a plugin that allows an easy button to a WC item. Maybe use this in conjunction with dynamically creating WC products 

https://wordpress.org/plugins/woocommerce-quick-buy/

This explains how to dynamically add a WC product. Maybe set the SKU as the listing ID to keep things in order and synced.

https://devnetwork.io/add-woocommerce-product-programmatically/

These explain how to add products to the cart. Here’s a couple things that need to be done.

https://www.businessbloomer.com/woocommerce-custom-add-cart-urls-ultimate-guide/

https://quadlayers.com/woocommerce-add-to-cart-function-programmatically/#:~:text=Easy%20peasy.,cart%2D%3Eadd_to_cart(%206%20)%3B

• Before adding an item to the card, clear the cart first. Otherwise the cart will just build over time of they don’t complete the sale.
• Add the service fee before the item being reserved. The serice fee is product # 3127