@Override
    public PasswordlessAuthenticationRequest parse(final String username) {
        val credential = new BasicIdentifiableCredential(username);
        val result = surrogateCredentialParser.parse(credential);
        if (result.isPresent()) {
            val sr = result.get();
            return PasswordlessAuthenticationRequest
                .builder()
                .providedUsername(username)
                .username(sr.getUsername())
                .properties(CollectionUtils.wrap(PROPERTY_SURROGATE_USERNAME, sr.getSurrogateUsername()))
                .build();
        }
        return PasswordlessAuthenticationRequest.builder().username(username).build();
    }
Request property that indicates the surrogate username, if any.
support/cas-server-support-surrogate-webflow/src/main/java/org/apereo/cas/web/flow/passwordless/SurrogatePasswordlessAuthenticationRequestParser.java