Error "in order to continue installing you must be an owner" doing software update on Mac

If you receive this error when doing software updates on a Mac, open Terminal and use this command to find the Secure token status for accounts on the device. Replace admin with the name of the user account you are checking

sysadminctl interactive -secureTokenStatus admin

Once you have a known admin account with secureToken enabled, run the scripts below

Replace these values with values for the machine

• admin - the username of a known admin user (one with a secure token enabled)
• addAdminUserPasswordHere - the password for the known admin user
• jdoe - the usual username the user is using when they receive the error
• addjdoePasswordHere - the password for the usual username the user uses

sysadminctl -adminUser admin -adminPassword addAdminUserPasswordHere -secureTokenOn jdoe -password addjdoePasswordHere

And then

diskutil apfs updatePreboot /

to allow that user to unlock FV at boot