If you are a seller on Amazon, you can view your sales of several months through Seller Central. The specific steps are as follows:

1. Log in to Seller Central: Open the Amazon Seller Central website (sellercentral.amazon.com) and log in with your seller account and password.

2. Enter the sales report page: On the homepage of Seller Central, click the "Reports" tab, and then select the "Performance" option to enter the sales report page.

3. Select the sales report time range: On the sales report page, you can select the time range to view. Click the "Time Range" drop-down menu at the top of the page, and you can select "Daily Report", "Weekly Report", "Monthly Report", "Quarterly Report" or "Yearly Report", or you can choose a custom time range.

4. View sales: After selecting the time range, the page will display data such as sales, order quantity, refund rate, etc. within the time range. You can view the total and average sales under the "Summary" tab at the top of the page, or view daily, weekly, and monthly sales details under the "Orders and Sales" tab at the bottom of the page.

It should be noted that the sales report in the Seller Center usually has a certain delay, so if you want to view the most recent sales data, you can select "Daily Report" or "Weekly Report".