Display in Frontend counter for nb products sold ?

Hi,

You can use such module in order to add your PHP code inside a module on your Joomla website:
extensions.joomla.org/extension/blank-module
In it, do first a query on the hikashop_order table in order to get the order_id of all the orders confirmed in that period and then do a second query to sum the order_product_quantity field of the hikashop_order_product table with the order_id in the list of the order_ids you got from the first query and you'll get your total number that you can just echo.