Most United iPads cannot load the Apple App Store therefore you can't install/update ezccs. The iPad belongs to United and United chooses what goes onto, or not as the case may be, onto their iPads.
You must manage your own subscriptions. If you have a separate subscription for the United iPad that you don't want anymore, only you can cancel it.
How to manage subscriptions https://support.apple.com/en-us/HT202039