Created attachment 862600 [details]
Installation of cups-pk-helper through transactional-update-shell
This is a workaround, after installing "cups-pk-helper" and rebooting, the
Unlock button in Gnome Setting for Printer shows up and I was able to invoke
the password prompt and add my printer. I suggest that the package
"cups-pk-helper" should be added to the packages that are installed by default
during installation.