To uninstall an app from your site, please visit the Apps tab in your Cloudflare dashboard > Installed Apps card > Click Edit Install on the app you wish to uninstall. From there you can click "Uninstall" at the bottom of the page.
Please take a moment to provide feedback in the prompt which will appear. The feedback allows us to help app creators improve their apps over time. Also consider searching in Cloudflare Apps for an alternative app, it's possible there is already one available which will better serve you.