Adding & Removing User Licenses
To add or remove a user license, click 'Payment & Subscription' in the user dropdown on the top right side of the navigation bar.
On the Payment & Subscription page, click any hyperlink in the 'Subscription Information' section to open the 'Edit Subscription Information' modal. You can adjust the number of licenses in your account from the plan dropdown, then save.
Once more licenses have been added, you can use them by inviting new users to your account.
If you are decreasing the number of licenses, you will first need to be sure they are not attached to any active users in your account.