How to display a message telling you to restart after installation on MacOS 11.0 (Big Sur)

I want to restart after installation, so I added the attribute onConclusion = "RequireRestart".
It reboots after installation, but MacOS 11.0 (Big Sur) no longer displays the following message telling you to reboot before installation.
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When this software finishes installing, you must restart your computer.
Are you sure you want to install the software now?
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Is this a specification change in MacOS 11.0 (BigSur)?
How do I display a message telling me to reboot after installation on MacOS 11.0 (BigSur)?
How to display a message telling you to restart after installation on MacOS 11.0 (Big Sur)
 
 
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