Select the setting in the sidebar that you should use to turn on Lockdown Mode.
From the sidebar, click Privacy & Security. Scroll down, click Lockdown Mode, then click Turn On.
https://support.apple.com/en-us/105120#:~:text=From%20the%20sidebar%2C%20click%20Privacy,Mode%2C%20then%20click%20Turn%20On .
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