Listing Items on eBay using a Staging Site
It is not recommended to list items to eBay from a staging site. When a listing is added or revised on eBay, both the images and the widgets that show other items point to the URL of the website the listing was added / revised from. If you list items from a staging site, those URLs will point to the staging site and the images and widget data will be loaded from there. When you later move to your live site, the URLs will continue to point to your staging site.
You should rather test listing a handful of products on your staging site until they appear the way you want them to. Then you should remove these listings and list them to eBay on your live site.
What do I do if I listed items with my staging site but am now on my live site?
You will have to revise all of your listings on your live site, which will change the URLs on eBay to point to your live site.