Every service that I've seen that uses TOTP 2FA will also give you a list of fixed backup codes and strongly encourage you to keep them somewhere safe. There ar

Every service that I've seen that uses TOTP 2FA will also give you a list of fixed backup codes and strongly encourage you to keep them somewhere safe. There are also TOTP apps that will let you make a backup of your codes, to also be kept somewhere safe. Of course it's the user's responsibility to actually keep backup codes somewhere where they can definitely be accessed in case the phone is lost and also can't be stolen easily. Ditto for a app backup. Sounds straightforward, but easier said than done.