This is TOTP. I use my password manager for that. I used to use Bitwarden, but I recently switched to 1password.
SSO means single sign on. If I sign on to Google, it automatically sign me on other apps. I use a forward auth on my self hosted services. I used to use authentik but I switched to google since it just works much better. If Google makes a shitty move in that department, I can always fall back to authentik.
I don’t mind using proprietary softwares if they’re good, I just prefer to think about an alternative in case I need to switch.
The worst I did is wanting to replace the WAN interface on my Opnsense router. I didn’t check properly and replaced my LAN interface instead, rendering the router inaccessible and fucking up my network. Luckily, its a VM on proxmox that was still accessible from IP. I just opened a console to the VM and found out that the whole configuration is in a file. Also, a copy is saved with every configuration change. I just found the right one to restore and voilà! My network was back up.