Please follow the steps mentioned below to apply a coupon while creating an invoice:
Step 1: Go to Bills >> Sales >> Click on +Invoice
Step 2: Enter the necessary details
Step 3: Scroll down >> Click on Add Extra Discount/Coupons
Step 4: Click on + Add Coupon
Step 5: Select the desired coupon and Click on Apply
Step 6: Click on Save
Step 7: Now, click on Create to create the invoice






