"Двоетапна перевірка" is a default combination of words that Google and Facebook use instead of "двохфакторна авторизація". I've also ommited some words, like in a vernecular expression "добре пам'ятати", to make the translation more succinct. By replacing "і переконайтеся, що без проблем можете увійти" with "аби не втратити доступ" I've made the translation more natural, because the word "аби" explains why you need to check your password.