Plugin should be registered in the same way as software - using license key, first name and last name. See Store Manager Support
regarding registration and possible problems. You can reset plugins license in the same way as main software license.
- After purchase all customers receive email notification with registration information, find License Number (Regcode) there.
- Open "Preferences" and activate "Plugins" tab to see the list of available Plugins and their information. Plugin is unregistered now.
- Click on registration status, QuickBooks Integration Plugin registration window will appear.
- Enter your registration information: license key, your first and last name (as it appears in your license account)
- Press "Ok" button to apply changes.