When you first log in, you will see a message stating that you need to set up two-factor authentication. You have 3 attempts to do this before you will be locked out of the site. If you are already logged in, you can set up two-factor authentication by going to your account and then selecting the Security tab.
When you click the link to set up two-factor authentication, you will be taken to the Security tab of your account. The TFA status will be “TFA disabled.” Click the “Set up application” link under the TFA application heading. (You can generate recovery codes before or after you set up two-factor authentication. If you want to generate them before setting up TFA, click "Generate codes" under the Recovery Codes heading and move to Step 6 for instructions. Then after they are set up click "Set up application" and move on to Step 3.)
After you click “Set up application,” you will be required to insert your password again and click the “Confirm” button.
After validating your account by re-entering your password, you will be shown several options for authentication apps. Once you have chosen and downloaded an app, you will need to use the app to either scan the QR code or to enter the text code given. Once one of those things is done, you should receive a verification code from your app. Enter that into the “Application verification code” box at the bottom of the screen and click the "Verify and save" button.
If your setup was successful, you should now see a screen with the message "TFA setup complete." and status will now be "TFA enabled." Two-factor authentication should now be set up on your account. If you would like to generate recovery codes, click "Generate codes" under the Recovery codes heading and move to Step 6.
You can generate recovery codes by clicking "Generate codes" under the Recovery Codes heading either before or after setting up two-factor authentication. Once you click "Generate codes," you will be required to insert your password again and click the “Confirm” button.
You should now see a screen with your recovery codes. These codes can be used to log in if you don’t have access to your app. You will need to PRINT, SAVE, or WRITE these down in a safe place in order to use them later. You also have the option to save them in your account, but you won't have access to them again unless you are logged in, so PRINT, SAVE, or WRITE them in a remote safe place as well.
If you choose not to save the codes and click the "Cancel" button, you will see a message saying, "TFA Setup canceled." TFA is not actually canceled and if you look at the status you will see that it still says "enabled."