As others are saying, you can store your TOTP code in a password manager, and if you lose you phone re-add it. You can also use something like oathtool do generate these one time passes at the command line.

I had a similar question and wrote up how I'm doing it here:

https://earthly.dev/blog/multi-factor-auth

Oathtool:

https://www.nongnu.org/oath-toolkit/oathtool.1.html