@Juan Pablo Roa ,
There is no way to recover the codes if the backup failed or if you did not initiate recovery the moment you installed Authenticator on your new device. Please check the article about recovery and backup of authenticator . Recover your account credentials on your new device by first initiating the recovery as shown in the picture below.
If by mistake you used "ADD account" on this screen rather than "Begin recovery" , your old backup will get overwritten as the new authenticator instance does not have any account details yet . So a recovery needs to be done first before you can add a new account . Add account is for adding new account . for any exiting account you need to signin using the begin recovery option whenever you change devices . In this case you would have to use other MFA methods like recovery codes from each service you had setup MFA for in the Microsoft authenticator application.
Thank you .