According to bundled plugins policy https://help.market.envato.com/hc/en-us/articles/213762463-Bundled-Plugins
Some plugins may ask for a purchase code for registration/activation once installed, however, you can simply ignore these messages as bundled plugins do not require activation or registration. The plugin will still work as intended with the theme once the theme has been activated/registered.
So, just close that message of the mentioned plugin. Follow the docs to update plugin https://xstore.helpscoutdocs.com/article/37-plugins-update I would recommend you to disable the plugin before the update.
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.