You should be notified 1 month in advance of your license's expiry. To renew your license please contact our sales team at email@example.com to obtain a new license key.
Once you have been sent your license key by our team you can click the 'Info' icon in the upper right of the application. This will open a modal with a 'Renew' button. Click this and enter your license key when prompted.
3. You should be notified if your license activation was successful. You can also return to the above pop-up window which should show that you are on the Professional version and display the expiry date of your new license.