c # Selenium connection proxy with authorization in FirefoxDriver

Tell me, please, the method / methods of connecting the proxy with authentication in FirefoxDriver. I tried many ways and got a little tired from the thought that in 2019 there was no easy way to connect a proxy with authorization in FirefoxDriver and СhromeDriver, following the example of how it is done in HttpWebRequest or even in the same PhantomJS (albeit via javascript). Ways that I tried at the moment:

1. Using alert and data entry. The method is good, but sometimes the browser hangs on the driver.SwitchTo (). Alert () line . After that, such a browser program can not be closed. Destroying a process is not an option.
2. Using extensions. As it turned out, when using the background mode options.AddArguments ("- headless") in the browser, the extensions refuse to work. Maybe there is a way to screw them in the background work of the browser, but I could not do it.
3. Searching for information on setting up a proxy through the firefox profile file also did not give a positive result. I did not manage to specify the login and password.

And is there an alternative to Selenuim? Maybe there are other platforms that work in the background, and in which it is possible to specify the data of the proxy without "dancing with a tambourine."