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If the phone was reset and Microsoft Authenticator was not backed up, the verification codes themselves cannot be recovered. However, there are two possible recovery paths depending on how Authenticator was configured before the reset.

1. If Cloud Backup was enabled in Authenticator (Android)
   If Authenticator had Cloud Backup turned on before the reset, the one‑time password (OTP) accounts (including third‑party accounts like Roblox) can be restored:
   • Install Microsoft Authenticator on the new or reset phone.
   • Open Authenticator and, before signing in to any account, select Restore from backup or Begin recovery.
   • Sign in with the same personal Microsoft account that was used as the backup account.
   • The OTP accounts (for example, Roblox) will be restored and the 30‑second codes will work again.
   If Restore from backup or Begin recovery does not appear, all existing accounts in the app must be removed or signed out first, then try again.
2. If Cloud/iCloud backup was not enabled
   If there was no backup configured, the codes stored in Authenticator are lost and cannot be restored from Microsoft’s side. In that case:
   • Use the account recovery options of each service that was protected by Authenticator. For Roblox, use its own account recovery or support process to remove or reset 2FA.
   • Once access to the Roblox account is recovered, set up Microsoft Authenticator again as a new 2FA method.
3. What can and cannot be restored
   • For third‑party accounts (such as Roblox, Amazon, Facebook, Gmail): the OTP codes can be restored only if a backup exists; otherwise they must be re‑added using each service’s 2FA setup.
   • For Microsoft personal accounts using OTP only: codes are restored from backup. If passwordless sign‑in was used, only the account name is restored and sign‑in is required again.
   • For work or school accounts: only the account name is restored; sign‑in is required again.

If unable to restore from backup and the Roblox account cannot be recovered using its own recovery options, there is no way in Microsoft Authenticator to retrieve the old codes.

References:

• Back up your accounts in Microsoft Authenticator
• Restore account credentials from Microsoft Authenticator