How to use existing Firefox profile in Selenium C#?

I found the answer on the official docs of selenium

var profileManager = new FirefoxProfileManager();
FirefoxProfile profile = profileManager.GetProfile("Selenium");
IWebDriver driver = new FirefoxDriver(profile);

Source: Selenium docs

You have to pass the profile object while instantiating the firefox driver. Like,

driver = new FirefoxDriver(profile);

See here for details.