FirefoxOptions firefoxOptions = new FirefoxOptions();
firefoxOptions.Proxy = pro; //my proxy object
firefoxOptions.AddArgument("-profile " + path); //path to the profile
FirefoxDriverService ffDriverService = FirefoxDriverService.CreateDefaultService();
ffDriverService.BrowserCommunicationPort = 2828;
PropertiesCollection.Driver = new FirefoxDriver(ffDriverService, firefoxOptions);

1561625708285   mozrunner::runner  INFO Running command: "C:\Program Files (x86)\Mozilla Firefox\firefox.exe" "-marionette" "-profile C:\Users\Usr\Desktop\fprofiles\pf1" "-foreground" "-no-remote"

"C:\Program Files (x86)\Mozilla Firefox\firefox.exe" "-marionette" "-profile C:\Users\Usr\Desktop\fprofiles\pf1" "-foreground" "-no-remote"

"C:\Program Files (x86)\Mozilla Firefox\firefox.exe" -marionette -profile C:\Users\Usr\Desktop\fprofiles\pf1 -foreground -no-remote