Change Add to Cart Text if the Product is Already in Cart in WooCommerce

functions.php

// Conditional function that checks if a product is in cart and return the correct button text
function change_button_text( $product_id, $button_text ) {
    foreach( WC()->cart->get_cart() as $item ) {
        if( $product_id === $item['product_id'] ) {
            return __('Already in Cart. Add again?', 'woocommerce');
        }
    }
    return $button_text;
}

// Archive pages: For simple products (ajax add to cart button)
add_filter( 'woocommerce_product_add_to_cart_text', 'change_ajax_add_to_cart_button_text', 10, 2 );
function change_ajax_add_to_cart_button_text( $button_text, $product ) {
    if ( $product->is_type('simple') ) {
        $button_text = change_button_text( $product->get_id(), $button_text );
    }
    return $button_text;
}

// Single product pages: Simple and external products
add_filter( 'woocommerce_product_single_add_to_cart_text', 'change_single_add_to_cart_button_text', 10, 2 );
function change_single_add_to_cart_button_text( $button_text, $product ) {
    if (  ! $product->is_type('variable') ) {
        $button_text = change_button_text( $product->get_id(), $button_text );
    }
    return $button_text;
}

// Single product pages: Variable product and its variations
add_action( 'woocommerce_after_variations_form', 'action_after_variations_form_callback' );
function action_after_variations_form_callback() {
    global $product;

    // Get the produc variation Ids for the variable product
    $children_ids = $product->get_visible_children();

    $ids_in_cart  = [];

    // Loop through cart items
    foreach( WC()->cart->get_cart() as $item ) {
        if( in_array( $item['variation_id'], $children_ids ) ) {
            $ids_in_cart[] = $item['variation_id'];
        }
    }
    ?>
    <script type="text/javascript">
    jQuery(function($){
        var b = 'button.single_add_to_cart_button',
            t = '<?php echo $product->single_add_to_cart_text(); ?>';

        $('form.variations_form').on('show_variation hide_variation found_variation', function(){
            $.each(<?php echo json_encode($ids_in_cart); ?>, function(j, v){
                var i = $('input[name="variation_id"]').val();
                if(v == i && i != 0 ) {
                    $(b).html('<?php _e('Already in Cart. Add again?', 'woocommerce'); ?>');
                    return false;
                } else {
                    $(b).html(t);
                }
            });
        });
    });
    </script>
    <?php
}

https://wordpress.stackexchange.com/questions/338728/change-add-to-cart-text-if-a-product-is-in-cart-on-woocommerce/