Bitwarden has TOTP included as a feature. Seems like lots of people don't like using it though, and see storing the 2FA keys with the passwords as "putting all your eggs in one basket".
Aegis seems to be the open source 2FA app of choice for privacy-minded people right now.
Idk about the central instance, but I use my bitwarden (specifically vaultwarden) instance for my TOTP keys. I can just autofill and then it copies the current TOTP key and i can paste it in to log into whatever i'm logging into!
Bitwarden provides a facility for MFA. Though there's an argument to be made against eggs + baskets. It might defeat threw purpose a bit.
I use Aegis which is opensource and easily encrypted and backed up locally.
Saved my ass where I accidentally deleted my 2FA for Bitwarden, thus locking me out in circle of shite. Aegis allowed me to roll back and pull in that one missing key without having to redo a load i'd made since the last backup and all was good.