.. _sms: SMS --- .. index:: SMS token The token type *sms* sends the OTP value via an SMS service. You can configure the SMS service in :ref:`sms_otp_token`. .. figure:: images/enroll_sms.png :width: 500 *Enroll an SMS token* When enrolling an SMS token, you only need to specify the mobile phone number. SMS token is a challenge response token. I.e. when sending the OTP PIN in the first authentication request, the sending of the SMS will be triggered and in a second authentication request the OTP value from the SMS needs to be presented. For a more detailed insight see the code documentation :ref:`code_sms_token`.