If you want to set up incentives on the basis of Item / Party, you have to configure it in Target Configuration. For this you can follow these steps:
Step 1: Go to Administration and click on configuration.
Step 2: Select Features / Options and click on Accounts here you will see a option called "Target" . Click on the check box to turn it on and save.
Step 3: Now, go back to Administration and click on configuration.
Step 4: Choose the voucher type for which you want to set the target, such as Sales or Purchase, from the Target Configuration menu.
Step 5: Next, you need to create a format and customize it according to your requirements, such as Party-wise, Item-wise, etc. You can also define the incentives for each target level.