If you have purchased a premium add-on, you have received a license key for it. You can use your license key to request premium support and receive automatic updates, just like all others WordPress plugins.
To get automatic updates, you need to save your license key and activate it.
Make sure your premium add-on is installed and activated. Then, go to Simple Calendar Settings page under Calendars menu item in the WordPress admin dashboard sidebar. From here, click on Add-on Licenses tab. You will see here a list of add-ons that you are running that require a license key. Enter your license key in the corresponding field for the add-on you want to activate. Mind that each key is meant for one specific add-on, you cannot swap keys. After you have entered your key, click on Activate.
If the activation is successful you should see an “activated” message next to the license field. If an error is returned instead, double check your license key and the instructions above. If the error persist and you are sure your license is valid, please contact support.
In the eventuality you will change your license key in future or you migrate your site to another domain, please deactivate the license by clicking on Deactivate button, this will also delete the license key from your site. If you want to enter a new license, enter a new one and click Activate again.