To add a reply to a review by a buyer on ServiceMela, you need to follow these steps:

1. Log in to your ServiceMela Account using your credentials.
2. Click on Services from the triple bar at the left corner of the page.
3. Select the service you want to reply.
4. Scroll down to view the Review section.
5. Click on Reply as Seller and write your reply.
6. Click on Reply to submit your reply.