Hello,

Thank you for reaching out to us regarding the issue you're experiencing with the backup code for 2FA. I understand that you've tried entering the code multiple times, with and without spaces, but it continues to return an error.

Based on the information you provided, it seems that you're using the Authenticator App on your Android phone for the 2FA process. To further assist you, I recommend the following steps:

Make sure that you have the latest version of the Authenticator App installed on your Android phone. If not, please update it from the respective app store.

Double-check that you are entering the backup code correctly. The code is case-sensitive, so ensure that you input the letters and numbers exactly as they appear.

If the issue persists, you can try removing and re-adding the 2FA authentication on your Firefox account. This can be done by going to your Firefox account settings and following the instructions to disable and re-enable 2FA.

If the problem still persists after following these steps, it may be best to seek further assistance from Mozilla Support. You can find more information and options for contacting support at the following link: https://support.mozilla.org/en-US/questions/1402329

I hope these steps help resolve your issue. If you have any further questions or need additional assistance, please feel free to ask.

Best regards, Suram Firefox Support Volunteer

Do not confuse the 10-digit 2FA recovery codes and the 32-character recovery key to bypass a forgotten password. The 32-byte recovery key is meant to be used when you forgot the password instead of a password reset as that would wipe all data on the Sync server. You only need one of the 10-digit 2FA recovery codes from the set you saved when you enabled 2FA.

• https://support.mozilla.org/en-US/kb/what-if-im-locked-out-two-step-authentication