If you lost your password and you are in a Duolingo classroom, you can go to duolingo.com, click on Login and select Forgot password. You will then receive a message from us at the email address you used to sign up.
If you are in a Duolingo classroom, your teacher or observer can reset it from their schools.duolingo.com account.
Warning: Do not join a classroom of someone you do not know, as they will be able to reset your password and make changes to your account at any time.