To Use a promotion in the Pos you will first need to Setup a promotion.
If you have selected Auto Selecting in POS in the promotion setup all you will need to do is select a service that is includes in a specific Promotion.
A message will appear in brackets showing the discount amount.
If Auto Selecting in POS is not selected.The Transaction can be discounted by selecting a service that is enabled for promotions.
once you have selected the service, Go to the bottom left of the screen to payment types and choose Promotion.
Once selected the promotion discount will be applied to the sale.