The general settings in Zenchat can be accessed by tapping or clicking your profile icon, then on "Settings", "General".
From here you can turn on or off the notification sound by toggling the "Sound" button. Additionally, you can find the version number of the app (not related to the mobile app version number), and choose to uninstall the app.
If you uninstall Zenchat, it will be removed from your Zenkit Suite. Any task lists created from within Zenchat will be deleted. When you click "Uninstall" you'll be shown a list of all lists created from within the Zenchat app. If you choose to go ahead with the de-installation, click "Done".