Fully offline 2FA TOTP generator?

You can use Aegis with Syncthing. Aegis can automatically backup your codes to a JSON file. You can create a dedicated folder for Aegis to backup to and add it Syncthing. you can also do manual exports to the folder For me, I have this same setup. Aegis to automatically export, Syncthing to sync the export to my server, and Restic with my bash script for scheduled backups You can also use Ente Auth in offline mode and import your export on your PC