To register and connect a Built-In
            Authenticator:
- Go to your
                Salesforce product’s login screen in a supported browser                and enter a username and password. 
- For products built on the
                Salesforce Platform: Click Choose
                Another Verification Method in the
                bottom left corner of the Connect
                Salesforce Authenticator screen,
                then select Built-In
                Authenticator. Select Built-In Authenticator from
                the list of verification
                methods for all other products that support this method. 
- Click Register.
- When prompted, enter the
                identifier for the built-in
                authenticator, such as a
                fingerprint, facial scan, or PIN,
                to finish logging in.
To log in using a Built-In
            Authenticator:
- In a supported browser, go to your
            Salesforce product’s login screen and
            enter a username and password, as
            usual.
- On the identity verification screen,
            click Verify.
- When prompted, enter the identifier for
            the built-in authenticator, such as a
            fingerprint, facial scan, or PIN, to
            finish logging in.
Requirements:
- The device, OS, and browser must
        support the FIDO2 WebAuthn standard.
- The built-in authenticator service must be
        enabled and set up ahead of time to verify
        a user’s identity.
- The user’s
        device must include a supported
        fingerprint, iris, or facial
        scanner for biometric authentication.
- Works only for logins to the device where
        the built-in authenticator exists.
Additional notes:
- Built-in authenticators are supported in
        Heroku, Marketing Cloud-Datorama,
        Marketing Cloud-Social, and MuleSoft
        Anypoint Platform. Additionally, products built on
        the Salesforce Platform are available
        as a Beta feature.
- For products built on the Salesforce
        Platform: an admin must enable built-in
        authenticators before users can select
        this option for MFA.
