To manage or cancel a Premium subscription with PUML you must do so through your App Store provider – Apple App Store or Google Play Store.

See more here: How to Unsubscribe PUML Premium

This is generally the same with most application only based services.

For IOS devices using Apple App Store you do this by going to ‘Subscriptions’ in your App Store/Apple account.

For Android devices using Google Play Store you go to ‘Payments and Subscriptions’ in your Play Store/Google account