Please, can you specify how do I have to upload the images with your extension?
How do I have to write the route of images in Excel?
What options I need to check in Settings of your extension?
Can you send me the URL of the extension manual? I can't find it
Images needs to be placed online on some public url. You can do that over FTP.
In images cell you enter comma separated list of absolute image paths starting with http(s)://...
In import/Export settings you need to enable image import.
You can read instructions under Help->Documentation