adding multiple products to cart from catalog page without refreshing page

Hi there,

I am hoping someone can help! I am using this code to create a multiple add to cart button on my catalogue page: https://claudiosmweb.com/woocommerce/woocommerce-loop-de-produtos-com-quantidade/#comment-2602

However the top block of code causes the page to refresh when the product is added to the cart, and the ajax code below, still works but the functions code breaks my site. Can you see the error here:

<?php
/**
 * Custom Loop Add to Cart.
 *
 * Template with quantity and ajax.
 */
if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly.
global $product;
?>

<?php if ( ! $product->is_in_stock() ) : ?>

    <a href="<?php echo apply_filters( 'out_of_stock_add_to_cart_url', get_permalink( $product->id ) ); ?>" class="button"><?php echo apply_filters( 'out_of_stock_add_to_cart_text', __( 'Read More', 'woocommerce' ) ); ?></a>

<?php else : ?>

    <?php
        $link = array(
            'url'   => '',
            'label' => '',
            'class' => ''
        );
        switch ( $product->product_type ) {
            case "variable" :
                $link['url']    = apply_filters( 'variable_add_to_cart_url', get_permalink( $product->id ) );
                $link['label']  = apply_filters( 'variable_add_to_cart_text', __( 'Select options', 'woocommerce' ) );
            break;
            case "grouped" :
                $link['url']    = apply_filters( 'grouped_add_to_cart_url', get_permalink( $product->id ) );
                $link['label']  = apply_filters( 'grouped_add_to_cart_text', __( 'View options', 'woocommerce' ) );
            break;
            case "external" :
                $link['url']    = apply_filters( 'external_add_to_cart_url', get_permalink( $product->id ) );
                $link['label']  = apply_filters( 'external_add_to_cart_text', __( 'Read More', 'woocommerce' ) );
            break;
            default :
                if ( $product->is_purchasable() ) {
                    $link['url']    = apply_filters( 'add_to_cart_url', esc_url( $product->add_to_cart_url() ) );
                    $link['label']  = apply_filters( 'add_to_cart_text', __( 'Add to cart', 'woocommerce' ) );
                    $link['class']  = apply_filters( 'add_to_cart_class', 'add_to_cart_button' );
                } else {
                    $link['url']    = apply_filters( 'not_purchasable_url', get_permalink( $product->id ) );
                    $link['label']  = apply_filters( 'not_purchasable_text', __( 'Read More', 'woocommerce' ) );
                }
            break;
        }
        // If there is a simple product.
        if ( $product->product_type == 'simple' ) {
            ?>
            <form action="<?php echo esc_url( $product->add_to_cart_url() ); ?>" class="cart" method="post" enctype="multipart/form-data">
                <?php
                    // Displays the quantity box.
                    woocommerce_quantity_input();
                    // Display the submit button.
                    echo sprintf( '<button type="submit" data-product_id="%s" data-product_sku="%s" data-quantity="1" class="%s button product_type_simple">%s</button>', esc_attr( $product->id ), esc_attr( $product->get_sku() ), esc_attr( $link['class'] ), esc_html( $link['label'] ) );
                ?>
            </form>
            <?php
        } else {
          echo apply_filters( 'woocommerce_loop_add_to_cart_link', sprintf('<a href="%s" rel="nofollow" data-product_id="%s" data-product_sku="%s" class="%s button product_type_%s">%s</a>', esc_url( $link['url'] ), esc_attr( $product->id ), esc_attr( $product->get_sku() ), esc_attr( $link['class'] ), esc_attr( $product->product_type ), esc_html( $link['label'] ) ), $product, $link );
        }
    ?>

<?php endif; ?>

And in the functions.php:

<?php
function cs_wc_loop_add_to_cart_scripts() {
    if ( is_shop() || is_product_category() || is_product_tag() || is_product() ) : ?>

<script>
    jQuery( document ).ready( function( $ ) {
        $( document ).on( 'change', '.quantity .qty', function() {
            $( this ).parent( '.quantity' ).next( '.add_to_cart_button' ).attr( 'data-quantity', $( this ).val() );
        });
    });
</script>

    <?php endif;
}
add_action( 'wp_footer', 'cs_wc_loop_add_to_cart_scripts' );

Or is there an easier way to add multiples from the cart on the catalog page? I also found this:

https://chrislema.com/improving-the-woocommerce-add-to-cart-button/

But when I copy the add-to-cart.php file to my child theme, it removes the add to cart buttons completely from the catalog page.

Thanks so much!