Hi @Bobdini_24,
There’s a little more information we need in order to better answer your question. What type of accounts are you using with the Duo Mobile app? You mention passcodes, so it sounds like you might be using third-party accounts like Facebook or Instagram. Did you back up your accounts on your previous device? You would have had to back up your device to iCloud as well as enable Duo Restore for Third-Party Accounts by setting a recovery password for the account in your Duo Mobile app.
Finally, did you attempt to restore your device from the iCloud backup you previously created on your old device? You should do this first, then open the Duo Mobile app, and you will have the option to reconnect your accounts from there. For third-party accounts, you’ll need your recovery password handy to be able to restore those.
If you’re locked out of your accounts or unable to restore for any reason, please refer to the instructions in this guide: Note about Instagram, Facebook, and other third-party account lockouts