code: def sms(self, client_id, phone_number):
          
  
          return self.post(
              'https://{}/passwordless/start'.format(self.domain),
              data={
                  'client_id': client_id,
                  'connection': 'sms',
                  'phone_number': phone_number,
              },
              headers={'Content-Type': 'application/json'}
          )
docs: Start flow sending a SMS message.