Woocommerce different tax setting

Hello,
I am trying to set a different tax on shipping cost in woocommerce. I have a 9% tax on products and a 20% tax on shipping. I added 9 and 20 with a checkbox on shipping in the standard rates, selected ‘standard’ in the ‘shipping class’ dropdown and nothing happens. I also added an additional tax class and selected that on the ‘shipping class’ dropdown and still no any result.
Your help will be greatly appreciated.
Thank you.