How to add extra discount to the existing invoice on Android?

Step 1: Kindly go to the bills>>Select the invoice>> Click on three dots.>>Click on edit>>Scroll down>>Click on discount/coupon>>Apply discount in rupees/percentage>>Save>>Update.

Step 2: Click on edit.

Step 3: Add extra discount.

Step 4: Click on the percentage>>Then, save.

Step 5: Check in the invoice.