So basically what title says.
Im using 2FA with google authenticator for multiple accounts. What if my phone gets stolen? Can I have some kind of backup? Or maybe sync with some self hosted service?
Bonus question: what 2FA should I use instead of google?
Personally I recommend just using KeePassXC and a KeePass app (I use KeePassium on iPhone).
You always have access to all your data that way. No company is monitoring you. A lot of apps make it very difficult to backup!
My totp database is in the cloud for syncing but needs a key file I don’t keep in the cloud (and a password). My passwords are entirely separate.