add_filter( 'wdp_save_cart_item_keys', function ( $keys ) {
 $keys[] = 'addons';
 return $keys;
});

add_filter("wdp_get_product_price", function($price, $product, $price_mode, $item_meta){
  if( !empty($item_meta["addons"]) ) {
    foreach($item_meta["addons"] as $addon)
      if( !empty($addon["price"]) )
        $price += $addon["price"];
  }
  return $price;
},10,4);