Two-factor authentication was first added to 1Password in 2018. In other words, while you’ll still … U2F security keys work with 1Password using a new API called WebAuthn, with 1Password developer Jasper Patterson saying:
We’re excited to be among the first services to adopt this new browser standard. Keys are currently limited to supported desktop browsers. WebAuthn is backwards-compatible with U2F, so all certified U2F security keys will work with our WebAuthn-enabled flow. What you need to know
1Password now works with U2F security keys for two-factor authentication. 1Password is implementing U2F keys as a new method of secondary authentication. After rolling out support for two-factor authentication via authenticator apps in 2018, 1Password now works with physical U2F security keys. 1Password, my personal password manager of choice, is getting a big upgrade to make it even more secure than it previously was. It’s currently limited to 1Password.com on supported browsers.