You can turn off 2FA if you have your backup codes by heading to User Settings and selecting Remove 2FA.
A 6-digit code will be required, but one of your backup 8-digit codes will work.
Note: Enter your backup codes exactly as written, without any dashes or spaces. You'll receive an incorrect code error if there are any spaces or dashes.
Note: Discord will be unable to delete 2FA and you will need to register a new account if you do not have access to your backup codes. You cannot receive fresh backup codes from Discord if 2FA removed.
