How to install the buyme script on Wordpress?

Question

WooCommerce

Please help me install the buyme script. I can't install the script in any way, and paying $60 for installation is nonsense. I am new to wordpress. The instructions say: "First you need to set up the product. To do this, assign class="b1c-good" to any block that includes the name of the product and the "buy" button. But they don't say where to look for this block. I can't find it. Maybe Who can tell? Thank you in advance.