How to add extra for a room?

Adding extras for rooms as follows:

After the receptionist is logged in My-dox system, go to Menu Extras room, click on the search box (Quick search). At the bottom, new window will pop up with the best selling and last sold products. From there, choose the product / service that the customer has ordered for the room, click on the right Sell button. Then fill in the data in the table - quantity, enter the discount, if any, to which client is, for which room.