Hey im a newbie and Onlykey will be my first Hardware Password Manager.
I would like to know if I could use 2FA without using Google Authenticator or Yubico One-Time Password?
How it works?
The users guide is a good place to start it describes setting up OAUTH-TOTP (Google Auth), Yubico OTP and FIDO U2F - OnlyKey User's Guide | Docs
You can also google any of those and find lots of information online about how each works. TOTP is a 6 digit code that is typed, Yubico OTP is a long OTP that is typed, with FIDO U2F nothing is typed the website just prompts you to touch your device to login.