If necessary, you can lock your users' macOS devices via the management portal. Users will then no longer have access to the devices. A special unlock PIN is required to unlock the devices.
- Open Device Management under Administration→ Devices.
- Select the Mac you want to lock in the left column (left arrow in the image).
- Then click Lock Device (right arrow in the image).
- Create a six-digit Unlock PIN that can be used to unlock the Mac after it has been locked (example shown in the image).
- Then click OK. The Mac will now be put into a secure state and can only be unlocked using the PIN you set in the last step.