If default currency for your website is NOT Rial or Toman, the price will be calculated into Rial currency by defining acceptable currency for the plugin.
Acceptable currency for Iranian payment gateway is Rial. If default currency for your website is Toman, you can change the setting for sending correct currency to your ZarinPal payment gateway.
Guide for downloading the plugin :
first, add the plugin to your shopping cart. This product is Free and in order to download it, you should finish the checkout process without paying any cost.
after submitting an order, go to order details page or "packages" tab in your profile page. you'll be able to download the plugin via the provided link in this page.