If you are on iOS, I recommend using the following:

https://ente.io/auth/

It’s open-source and recommended by PrivacyGuides.

I’m on Android, where that’s also an option I believe, but I’m using Aegis.

Bitwarden also came out with an open-source MFA app, though it’s a bit new so I’d recommend waiting to see what folks say about it.

Raivo uses to be a good (and the only decent) choice for iOS but I believe it was acquired by an insidious company.