How do I add taxes?
From any page of the menu at the top-right, select Settings.
In part Tax default, you can add, by selecting from drop-down list, of the proposed system
or by clicking on the Add button and then enter your tax..
In the opened page, right in Tax, enter the name (eg. 10%) and in the box below Tax percentage enter the digit for the desired tax (eg. 10).
Click Save to save the new tax and choose Settings again to return to the previous screen.
Select newly introduced tax, select the Save button at the end and you are done.