Thanks for posting in the Apple Support Communities zman365,
Try disconnecting any connected devices, except for the power supply, and attempting to update again using the steps on the following page: Update macOS on Mac
If you encounter the same message again:
1: On your Mac, do one of the following:
• If you’re using Family Sharing: Log in to your Mac user account, then make sure you’re signed in with your Apple ID.
• If you aren’t using Family Sharing: Log in to a family member’s Mac user account.
2: Choose Apple menu
> System Settings, then click Screen Time
in the sidebar. (You may need to scroll down.)
3: If you’re using Family Sharing, click the Family Member pop-up menu on the right, then choose a family member.
4: Turn on Use Screen Time Passcode.
5: Enter a four-digit passcode, then enter the passcode again to verify it.
6: Enter your Apple ID and password so you can later reset the Screen Time passcode using your Apple ID.
Set, change, or remove a Screen Time passcode on Mac
We hope this helps!