Listing builder – WooCommerce “add to cart” button

<?php

// Add the following to custom-hooks.php or into your (child) theme's functions.php
// Then add a Listing Builder Button item, and give it the Unique name 'add-to-cart'.

add_filter( 'facetwp_builder_item_value', function( $value, $item ) {
    if ( 'add-to-cart' == $item['settings']['name'] ) {
        global $post;
        $value = do_shortcode( '[add_to_cart id="' . $post->ID . '"]' );
    }
    return $value;
}, 10, 2 );