Applies to: Photo Ephemeris Web Pro (aka TPE Web App v2)
To manage your subscription, click the PRO badge at the top right of the screen:
Your current and any past subscriptions will be shown on the next page:
Available options are displayed after clicking 'Manage Subscription':
Click to update or cancel. You will be shown a popup window where you can confirm the changes.
To update your Payment Method, click Update: