Firefox extension 1.9.1 doesn't work with Orion RC 0.99.126.4.1-rc. When asked to sign into my Proton account, I just get an error screen that states "Oops. something went wrong".
Using the Chrome extension allows me to log in, but there doesn't appear to be any way to allow the password info to be populated. There is no Proton Pass button in the credential fields.