Schedule an interview against a candidate's application at a specific slot on the job's interview plan. application_id, job_interview_id (the interview-plan slot), starts_at, ends_at, and external_event_id (the id of the matching event on the organizer's external calendar) are required. Provide the panel via interviewers, where each entry must include response_status and identify the interviewer by user_id, email, or employee_id. location and video_conferencing_url are optional metadata copied onto the Greenhouse record; this endpoint records an already-scheduled calendar event rather than creating one on an external calendar.