There are a few different ways to apply a discount within BPro. These are done in the "Checkout" tab of a job. You will first want to ensure you click on the "Adjust Invoice" button in the top right corner of the job. The prices and ability to provide discounts is locked unless this button is clicked: 

BPro will now give you the ability to provide discounts to the job in a couple different ways: 

The blue option is if you want to make either a percentage discount or take a specific dollar amount off the price of an individual item within the cart. 

The green option is if you want to quickly change the default price assigned to the product/service to something else. 

The orange option is if you want to change the price for all items in the cart at one. These are also considered "bulk discounts". 

Once you have entered your discounts they will reflect the overall price of the job. You will now want to click on "Save Invoice" in the top right corner: 

This will save all changes and will track the changes you have made. In order to look at all the changes that have been made you will scroll to the bottom where you will see a "Change History" tile. This is where you can view the changes that have been made to the invoice including any discounts applied after the fact.