Update Participant Attendance BatchONETAPCHECKIN_UPDATE_PARTICIPANT_ATTENDANCE_BATCH
Apply one shared check-in, checkout, undo check-in, or undo checkout operation to 1 to 25 participants in input order, using one provider request per item. Items execute independently: validation, not-found, and conflict failures are reported per item and do not stop later items, so partial updates are possible and successful changes are not rolled back. Authentication, rate-limit, server, unexpected client, and malformed-success failures abort the batch. Check-in never sends visitor alerts.