First, you have to login to My Account from the Wp Author Box to cancel your subscription.
Enter your username and password to log in to the account.
Click Subscription to get the details about the plugin.
In the Subscription >> Actions section, you will see an option to cancel the subscription.
Once you click the Cancel option, you will get a pop box to reassure you.
When you click “OK“, the subscription will be cancelled. Here, you can see the status.