How to access eBay specific meta data via the WooCommerce REST API
Out of the box WooCommerce doesn't let you access eBay specific custom meta fields via their REST API. Only specific known product properties can be updated that way, which is intentional for security:
Even though they mention a possible change in the future, this won't apply to meta fields starting with an underscore - which is true for almost all meta fields used by all plugins, including the meta fields used by WP-Lister.
However, there is a plugin on Github which does allow access to all custom meta fields via the WooCommerce REST API:
Once installed you will have access to all the eBay specific custom meta fields like _ebay_title, _ebay_price, etc. For a complete list of all custom meta keys (field names) see Can I update my inventory from a CSV file?