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When it first prompts it will look like this:
(If the deadline is close, the "Defer" time will be the time until the deadline, otherwise it will be the number of minutes configured in the "Default Deferral Timer" option)
If you click on Restart, on an Apple Silicon Mac you'll get the user auth dialog:
NOTE: the password will get saved in the user's keychain - next time the Mac needs updates, the user will not be prompted!
IF you enter the wrong password twice it will abort, and you'll get the error dialog:
Once you've entered your password (or immediately on an Intel Mac) you'll see the restart message:
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