public IActionResult GetAttendedConferencesFirst([FromBody] GetAttendedConferencesFirstModel model)
        {
            List <ConferenceAudienceModel>          conferencesAudience      = _conferenceRepository.GetConferenceAudience(model.Email);
            List <ConferenceDetailAttendFirstModel> attendedConferencesFirst = _conferenceRepository.GetAttendedConferencesFirst(conferencesAudience, model.StartDate, model.EndDate);

            return(Ok(attendedConferencesFirst));
        }