After enabling two-step verification, you'll receive ten backup codes. Each 8-digit code can be used once to access your Dropbox account in case of emergency or if you are having trouble receiving a 2FA code through the mobile app or via text message. To find your backup codes, access your account settings on dropbox.com. Navigate to the Security tab and scroll to Two-step verification. Select Show next to Recovery Codes. When entering a backup code, be careful to transcribe the code correctly. The number “1” can look like an “L,” a “0” (zero) can look like an “O,” etc.