You can observe all Products added to M2E Pro Listings or add as an Unmanaged Listing in eBay Integration > Listings > Search.

Use the filters to find the product you want to manage. If an eBay Item ID is available, clicking it will take you to the listing on eBay. Clicking the  icon in the Manage column will take you to the M2E Pro Listing's products page, where you will be able to manage its settings.