Selenium - User prompt of type promptUserAndPass is not supported

It seems that HTTPAuth dialogs are not supported by any drivers at the moment.
Firefox implemented an workaround which does not work anymore in 67.0. It appears they cannot start adding support for the HTTP authentication prompt right now, due to missing specifications.

https://bugzilla.mozilla.org/show_bug.cgi?id=1556026

https://bugzilla.mozilla.org/show_bug.cgi?id=1556307

https://github.com/w3c/webdriver/issues/385

I've managed to workaround this problem by installing Firefox 66.0 under a different name and then mentioning its location when calling the FirefoxDriver, like @elead1 did.

from selenium.webdriver.firefox.firefox_binary import FirefoxBinary
from selenium.webdriver import Firefox

path = FirefoxBinary("/path/to/Firefox2/firefox-bin")
browser = Firefox(firefox_binary=path)

I don't have enough rep to comment and I know this isn't "solving" the problem, but I was able to work around this problem by using the Firefox ESR.

You can install the ESR parallel to your main Firefox installation, and then specify which binary the FirefoxDriver will use:

driver = webdriver.Firefox(firefox_profile=profile, firefox_binary="/path/to/esr/binary")