Step 1: Navigate to the Customise UI.

Step 2: Choose to hide the discount box from the login section. Select coupon hide.

Step 3: Save your changes.

Step 4: Proceed to the address section.

Step 5: In the coupon section, uncheck the box and save your changes.

Step 6: Next, visit the payment section.

Step 7: Click on coupon.

Step 8: Save your changes.

By following these steps, you've successfully removed the discount box from checkout.