ShipScript has been an eBay Community volunteer since 2003, specializing in HTML, CSS, Scripts, Photos, Active Content, Technical Solutions, and online Seller Tools.
eBay does not have a feature to integrate listings with other platforms (realistically, why would they provide a service to deplete their own listings in favor of other venues)?
However, there are third-party services that will integrate with a multitude of platforms, so if that is your intent, you may want to investigate those third party services.
