def execute(cls, transaction_id, phone, message):
        kwargs = {
            'MessagingMode': 'asynchClientServer',
            'AP_TransID': cls._format_transaction_id(transaction_id),
            'MSISDN': phone,
            'DataToBeSigned': '%s %s' % (cls.settings['message_prefix'], message),
            'SignatureProfile': cls.settings['SignatureProfile'],
        }
        return super(SignatureRequest, cls).execute(**kwargs)