Bundled Plugins License & Activation Questions
When a premium plugin is included for free with a WordPress Theme you can use the plugin without any issues. The plugins are fully functional even though you don't get a plugin purchase code for activation.
Since you purchased a bundled product you do NOT have a purchase code for that plugin so you can’t enter anything in this field. Updates to the plugins are provided when the theme itself is updated.
However, if you want automatic updates and support from the plugin developer you need to purchase it separately (this is 100% optional).