You're looking at the documentation for Liquid Ajax Cart v1. Go to Liquid Ajax Cart v2


Liquid Ajax Cart ajaxifies all Shopify product forms by default.

But, for example, if you want to ajaxify only product forms with the data-my-product-form attribute then provide a function as the productFormsFilter parameter:

<script type="module">
  import { configureCart } from '{{ "liquid-ajax-cart-v1.11.2.js" | asset_url }}';

  configureCart('productFormsFilter', formNode => { 
    return formNode.hasAttribute('data-my-product-form') 

Liquid Ajax Cart will call your function and pass the Element object of the product form that is going to add a product to the cart, and proceed with an “Add to cart” Ajax request only if the function returns true.