If you want to view the sales of a certain product on eBay, you can follow the steps below:

1. Log in to your eBay account and enter the product name or keyword you want to view in the search box.

2. On the search results page, find the product whose sales you want to view and click to enter the details page of the product.

3. On the product details page, scroll down until you find relevant information such as "sales record" or "sales statistics". Some product details pages may not have this information.

4. In the sales record or sales statistics, you can view the sales quantity, sales amount, evaluation and other information of the product. If the sales information is not displayed, it may be because the product has no sales record or insufficient sales record.

It should be noted that the sales information on eBay is provided by the seller and may have certain errors. If you want more accurate sales information, you can try to contact the seller or check the sales data from other channels.