Bitwarden Authenticator is a standalone app that is available for everyone, even non-Bitwarden customers.
In its current release, Bitwarden Authenticator generates time-based one-time passwords (TOTP) for users who want to add an extra layer of 2FA security to their logins.
There is a comprehensive roadmap planned with additional functionality.
Available for iOS and Android
This dumps it to a file, then it’s on you to copy it somewhere else.
Or
I think this one is automated, but I personally don’t use it, I just back it up manually when I add something new. I keep a completely functional 2FA app on my desktop, so I always have a backup in a pinch.