How can i give an item for free of cost

How can i give an item for free or item with zero price, as far as i know it is not possible to process payment with zero price item exist.
Any suggestions?
thanks !

If you select the item you want to give for free, then a button appears on the left column, GIFT, you press there, and that items will be gifted or will be zero price!!!


Thanks very much @gerlandog
is it possible to change it to free in the bill and display?

It actually does that!

If you look closely it has (in the display) the price butter under it shows GIFTED
In the printer template you can put whatever text you like, mine is PROMO