Clicking on a tab or section control in your form will show a Security tab, along with the Settings and Style tabs, in the properties pane. The top portion of the tab displays a drop down of
In the section, Manager Approval, the checkbox control used by the manager to approve or reject the request, has the required property selected but it will be treated as not required so the employee can submit the form. The Control Security Tab works in conjunction with forms in a flow. See this Leave Approval Workflow Tutorial for more information.
If a section is assigned a role that is deleted by the tenanct admin, the section will not be visible to anyone.
The lower portion of the Security tab concerns Electronic Signatures and is only relevant for a section control.