I don’t have my phone on me right now
If you don’t currently have access to your phone, you’ll need to log in using one of your backup codes. Enter one of your backup codes in the box above and log in as usual.
Each backup code can only be used once, so once you’ve logged in, you should open your two-factor authentication settings (within your user settings) and generate a fresh set of backup codes if you’re running short.
I’ve lost or replaced my phone
Once you’ve logged in using a backup code as above, open your two-factor authentication settings and click the "Add another authentication method" link to add your new device.