GDPR requires you to be able to delete a given user and all its related data. Air360 offers a function that allows you to do just that. Simply go to a user profile and click the "Delete this user profile" button as shown below.
You will then be prompted to confirm you want to delete this user information.
As you see, Air360 keeps track of orders in order to keep consistency in your sales digits. The orders that were placed by this user will become orphans in the sense they won't be linked to any user anymore.