Hide fields in checkout based on specific products

To remove a custom field from the checkout in WooCommerce when a specific product is in the shopping cart, you can use the function woocommerce_checkout_fields and remove the field based on the product. Here's some sample code that might help you:

add_filter( 'woocommerce_checkout_fields', 'remove_custom_field_based_on_product' );

function remove_custom_field_based_on_product( $fields ) {
    // Hier die Produkt-ID einfügen, die das benutzerdefinierte Feld ausblenden soll
    $product_id = 123;
    
    // Überprüfen, ob das Produkt im Warenkorb ist
    foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
        if ( $cart_item['product_id'] == $product_id ) {
            // Wenn das Produkt im Warenkorb ist, entfernen Sie das benutzerdefinierte Feld
            unset( $fields['billing']['billing_custom_field'] );
            break;
        }
    }
    
    return $fields;
}

In this example, the custom field named billing_custom_field removed from the checkout if the product with the ID 123 in the shopping cart. You can customize the code to remove the custom field you want to hide and the product that triggers the action.