1. You should enable "Redirect customer to cart after adding a product" option
2. Alter "cart.php", find and replace this code:
PHP Code:
if (!empty($active_modules['SnS_connector']))
$is_sns_action['AddToCart'][] = $productid;
$return_url = 'cart.php';
with this:
Code:
if (!empty($active_modules['SnS_connector']))
$is_sns_action['AddToCart'][] = $productid;
$return_url = 'cart.php?mode=checkout';