Two factor authentication is normally set up with a phone number. When you sign in to an account secured with 2FA, a code is sent to your phone and the code needs to be entered on the sign in page in order to get into the account. The only problem is that if someone really wants to get into your account, a phone number isn’t the best tool to use to secure it. You can use alternative methods for 2FA. If you’re using it for Gmail, you can use the Google Authenticator app. Here’s how to set it up for a Gmail account.