Wordpress Plugin License

Hello, I want to download some Wordpress Plugin License to activate them at my Website. How can I do it? I really don’t found a way.
This is the plugin name - Grace Instagram Feed Gallery v. 1.1.14

How to contact an author to get support or for any technical query:

You can contact your author for better solution

Same question for a few other plugins. Can 't find how to get the license after adding it to a project…

For marketplace purchases the p/code can be found by following this link https://help.market.envato.com/hc/en-us/articles/202822600-Where-Is-My-Purchase-Code-

Elements downloads do not have p/codes because there is no support or updates