Importing existing Amazon listings
If you have existing listings on Amazon, they can be easily mapped to products in Magento / WooCommerce by performing an ASIN search.
Clicking the search button opens the ASIN search, which is described in detail in the How to list on Amazon help article.
When mapping to the ASIN for a product you already have listed on Amazon, the Magento / WooCommerce product is associated with and managing that listing. How much of that listing is managed by your catalog data is determined by the setting in the Catalog Data column.
The default is Use Amazon Catalog, meaning that your existing listing data except for price and stock level won't be overwritten by your Magento / WooCommerce data. You can change it to Use Magento Catalog / Use WooCommerce Catalog to control every aspect of the listing from within Magento / WooCommerce.