To return a product on Pinduoduo (拼多多), you can follow these steps:

1. Log in to your Pinduoduo account.
2. Go to the "My Orders" section.
3. Find the order containing the item you want to return.
4. Click on the order and look for the option to "Return" or "Refund".
5. Follow the instructions provided to initiate the return process.
6. Package the item securely and ship it back to the seller as instructed.
7. Once the seller receives the returned item, your refund should be processed.

If you encounter any issues during the return process, you can contact Pinduoduo customer service for assistance.