Passwords Mozilla Add-on does not install

I have Avast Pro 17.4.2294 with Win 10
Tried to install Mozilla Add-on from Browser integration. Allowed ipm-provider.ff.avast.com and install completed.
But no key appears in Mozilla browser (even after Restart).
I have read the Avast Password instructions and have tried Add-on install four times, always completes but cannot see key. Is there something else I need to do ?

Hi meonhouse,

do you still have a problem with Firefox extension? If so, send me a private message with your email address so that we can figure out what is wrong.

Thanks

Do you have the same problem with the latest version of avast ?

17.4.2294 is a old(er) version.