sample code showing how you can change the segment confirmation level or subscribe to the changed event using Integration API

SegmentConfirmationLevel.cs

var editorController = GetEditorController();
var segmentId = editorController.ActiveDocument.ActiveSegmentPair.Properties.Id.Id;

editorController.ActiveDocument.SegmentsConfirmationLevelChanged += ActiveDocument_SegmentsConfirmationLevelChanged;
editorController.ActiveDocument.ChangeConfirmationLevelOnSegment(segmentId, ConfirmationLevel.Translated);