Use a keyboard lock utility such as Keyboard Locker, KeyFreeze, or Kid-Key-Lock
On Windows, open Device Manager, find the keyboard, and disable the device
On Windows, use Group Policy or registry restrictions if available on your system
On macOS, use a third-party keyboard lock app
On Linux, use xinput to disable the keyboard temporarily
Use a laptop shortcut or function key if your manufacturer provides a keyboard lock feature
Enable a screen lock to prevent input while the laptop is unattended
Connect an external keyboard and disable the built-in keyboard if supported by your system
Use BIOS or UEFI settings if your laptop includes internal keyboard disable options