How to protect my authenticator app?

Authy and KeepassXC.

The idea is that if I have access to my phone number, I can recover the 2FAs using Authy. If I don't, I can use any free software to look at the KDBX such as KeePassXC where I've got the TOTP seed, and use that to login.

Both Authy and the KDBX require remembering a password.

Thanks, i don't want to use my phone number, it's not very secure.

and for KeepassXC, i need to keep the KDBX somewhere, in the worst scenario, what if i lost the KDBX? (my laptop is stolen, broken etc.)

Don't use any "accounts". Backup the QR codes on paper. (Literally, buy a cheap laser printer and use the browser print action when presented with one of those QR codes.)

good idea, i need to save something offline anyway.

With another authenticator app?