What's the concept behind having an Authy account? It converts a TOTP seed into a time-based TOTP code. No part of that suggests that you'd need an account.
It means getting access to your 2FA codes on a new device is as straightforward as installing the app and signing in. Other commenters have mentioned authenticator apps that let you transfer the codes by initiating a backup or generating a QR code, but that won't work if the previous device is at the bottom of a lake.
> authenticator apps that let you transfer the codes by initiating a backup or generating a QR code, but that won't work if the previous device is at the bottom of a lake.
You've got a strange definition of "backup" if you think it won't work after the subject of the backup has been destroyed. What would be the point of a backup that stopped working whenever you needed it?
That depends on whether the backups are automatic and ongoing, or if they're the "scan this QR code to transfer to a new device" type. The former will be fine if the original device is lost, the latter will not be.
