This is a trivial 'software requirements' problem
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17 - To unlock your device, enter your passcode on the lock screen.
18 - To appear to unlock your device, enter the secondary passcode (3968 or "F YOU") on the lock screen. The device will minimally unlock, allow access to a limited list of harmless data-free apps and only genuine-looking sample data. This will satisfy any legal requirement for unlocking your device while not actually unlocking your private data.
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Over to you Google and Apple.