Hello,
All our beloved users using Firefox 57 beta must be missing the Enpass extension as the Firefox has cut off the support for add-ons. There is a pre-released version of Enpass WebExtension exclusively for you available here on our website.
Please note, to make the Enpass WebExtension work for you, you need to have the latest Enpass v5.6 for Windows, Linux or Mac (website version) installed on your system. The Mac users those who are using the AppStore version have to wait until the update hits the store. We'll keep you posted for that.
Cheers!