I have tried in the past to get this to work but I continue to fail.
I have gone through the four step process in the GUI and it shows that it is set up and ready to go but it's not. It always goes back to the start (the Password Overview page, second image) and the extension shows it has not been activated.
For what it's worth, I did have a main password in the past that I have forgotten. If this is the problem, please delete any password database that is related to my account so I can start over.