If an employee can't cancel their own time off request, there will be two reasons for this:
Employee is trying to cancel time off request on or past the date of their requested time off, which is not possible. For example you request time off for 25-30 October, and you try to cancel it on 25 October.
Access to be able to cancel time off has been disabled in Employees permissions.
If you have admin access in Sage HR, and want an employee to be able to cancel their own time off request, you can enable this setting following the steps below.
Enable access to cancel own time off request
Click your name on top-right, then click Settings.
On the settings menu, click Permissions, then click Employees.
Select Allow employees to cancel their approved time off requests.
Scroll down and click Save.
Employees can now cancel their own time off requests.