Yeah but that's straight from within the app setting it up , so has to work with Google account maybe something there . The back up probably go to Google drive?
There's no backup and there's no chance to restore your in-app accounts after you delete the app. They just don't do it. Either you have this app coneccted to your account or you don't - it will work and offer you codes. You can check it by connecting the app to Google account and then deleting the account from your phone. App will still work without even offering you to reconnect it to Google account again.