Two factor auth in Plone 6

Sorry for not doing proper research yet… late sunday evening and customer wants answer tomorrow:

Is there some two way auth that will work with Plone 6 that will work in a 'only Plone setup' ?

It is for a (small) 'members club', so anything is of interest as long as it is 'considered safer than just password.

Have you checked this? https://github.com/collective/collective.googleauthenticator

Thanks: I discovered it '2 minutes ago'. I wonder: Is the 'GoogleAuthenticator app' OK to use (is it maintained and working on all phones' ?

Yes. you can also use some other apps, I personally use Aegis Authenticator but there are several others.

It looks like there are several things that need updating, currently I am stuck at:

from plone.app.users.browser.personalpreferences import UserDataPanelAdapter

which does not exist anymore (?)

I have to offer Two factor auth if l should get this project.

Does anyone have an idea how much work / money it will require to get something working ?

PS: I could probably used Python3/Plone5.2 if that is an option