Why is the discount window not appearing in purchase?
The discount window is not appearing in purchase voucher because the option of item wise discount is disabled. To enable it follow these steps:
Step 1: Open your company then go to administration menu and click on configuration sub menu.
Step 2: Select voucher series configuration and select the purchase voucher type then choose series main or etc.
Step 3: On right side click on voucher configuration and here set Y on item wise discount option and specify the discount structure then save.