Turn it on from Settings, under Your account. It keeps your account safe even if someone learns your password.
Lost your phone? On the code page, type one of your backup codes.
Lost those too? Press Lost your phone and your backup codes? on the code page. It turns off after 7 days, and we email you a button to stop it, in case it was not you.
Can’t find it?
Send us your question, and we’ll reply.