If you're needing to remove your Zoom Video Conferencing Account, you can do by signing into the Zoom account and following the steps below. 

1.) Sign in to the Zoom web portal as an administrator.

2.) In the navigation panel, click Advanced then App Marketplace.

3.) On the top right of the page, click Manage.

4.) On the left side of the page, click Added Apps.

5.) Identify the app to be removed (Cronofy) then, click Remove.

6.) In the Remove app pop-up window, click Remove.

That's it!