If you are trying to increase the user license count for Easy Reports or your trial period has ended and you are ready to subscribe, you can go to the Manage Subscription action available under the Related menu dropdown on the Easy Reports List page.
When you click on this link a browser window opens to a portal where you can change the license count, cancel the subscription or perform other actions.
Note that sometimes your browser may block the popup so pay attention to that. You also have to be a super user or have the Manage Subscription permission set assigned to use this feature.
You must have the Easy Report Manage permission set or be a super user. This permission set allows you to go to the web portal and manage your subscription (add / remove user licenses etc).