Users can delete themselves from the Webtop.com app.
A workspace owner is not able to remove his/her account if there are other members in the workspace.
First, the ownership has to be changed to another member, and only then an account can be deleted. If a workspace owner wants to be deleted, he/she needs to send a request to the customer support
How to delete the Webtop.com account (instructions for users with member/admin rights):