The following article explains how to allow users to Login Passwordless using a Security Key.

• Passwordless sign-in
• Security key

Follow these steps to enable passwordless sign-in with a Security Key:

1. Set the Authentication Profile as Identifier First.
    
2. Custom Login Page, aka Classic Login, must be disabled.
    
3. Disable Requires username or activate flexible identifiers.
   
4. Use my own database must be disabled unless Import Users to Auth0 is enabled.
   
5. New Universal Login Experience must be enabled.
    
   
6. In the Database, click on the Authentication Methods tab and Enable the Passkey option. Now click on Configure.
    
7. Now in the Passkey Policy be sure that the Passkey Challenge is selected the Passkey Button option.
    

Now that everything is set up, on the Login Screen a button that says "Continue with Passkey" will be displayed.

Once the "Continue with Passkey" button is clicked, the user will be prompted to select the type of passkey they want to continue with, and they can choose the USB Security Key.