When setting up a Merchant Center account, you can choose how you want to add your products. If you've already added products to your account, you can switch to another method whenever you want.
To ensure that your product data is easy to manage, it's only possible to use one method for adding products at a time.
When you switch how you add products, your existing products are deleted. If you want to reuse those products, include them when you use the new method for adding products. Before you choose another method, you're prompted to download your product information so that you can reuse all your previous details when you add the products again.
Any products that you added directly in Merchant Center's Product Editor won't be deleted when switching to another method.
How to download your product information
In your Merchant Center account, click Products
in the left navigation panel.
Click the All products tab at the top of the page.
Go to the right corner of the 'Add products' panel and click the download icon
to download your product information file.