Just to confirm, whether there is a way to block deletion of any entries entered in the system ?
Which edition? Desktop, server, or cloud?
Set a lock date: https://www.manager.io/guides/5510. But in the desktop edition, there is no restriction on the ability to change a lock date. Anyone with access to the machine and program is presumed to be the owner of the application. If you want to restrict different users, you need to use the server or cloud editions.