@Override
    protected Event doExecuteInternal(final RequestContext requestContext) {
        val registrationEnabled = casProperties.getAuthn().getMfa().getYubikey().isMultipleDeviceRegistrationEnabled()
            && MultifactorAuthenticationWebflowUtils.isMultifactorDeviceRegistrationEnabled(requestContext);
        MultifactorAuthenticationWebflowUtils.putYubiKeyMultipleDeviceRegistrationEnabled(requestContext, registrationEnabled);
        return null;
    }
This is {@link YubiKeyAuthenticationPrepareLoginAction}.

@author Misagh Moayyed
@since 6.3.0
support/cas-server-support-yubikey-core/src/main/java/org/apereo/cas/adaptors/yubikey/web/flow/YubiKeyAuthenticationPrepareLoginAction.java