Where can I get the license?

License for what exactly? If you are referring to the licensing of the plugin, that is something the original author would set that determines how a plugin can be used. Example licenses would be GPL, MIT, etc.

The plugin is not purchased? I thought it was just for shopping. I try to download it and it is not available. How can I get it, does the developer have a particular website?

The plugin was migrated and has no maintainer, so it would need to have someone to maintain it.