Not supported any more!
This addon heavily relies on legacy features, which will no longer be supported by Firefox 57+ and there doesn't seem to be a way to port the functionality to WebExtensions. There is a final, untested build which might still work with Firefox 56.
Replaces the default password managers storage with pass (www.passwordstore.org).
There are some configuration options exposed via the about:config interface. The scope is extensions.passmanager.*. For people using a command line password manager, this should be sufficient :-)
Because pass-manager replaces the default password storage backend, it is compatible with plugins like Password Exporter.